Knowledge base

Verified articles about specific Windows problems, each with a source you can check yourself.

• One app keeps closing by itself

  If one application keeps closing while Windows and other apps remain stable, start with that application rather than treating the whole PC as broken. Repeated crash events can show the application, faulting module and exception code, but those are clues rather than proof of the root cause. Check for updates and recent changes, then use the app's supported repair or reinstall path.

• Why is this app still running after I closed it?

  Closing an application's visible window does not always mean that every process belonging to the application has stopped. Some apps intentionally continue in the background to synchronize data, send notifications, update, or provide other services. First confirm that the process is still running, then determine whether its background activity is expected, useful, and materially consuming system resources before changing anything.

• Why are files and settings left after I uninstalled an app?

  Uninstalling an application does not guarantee that every file, folder, registry value, shortcut, or shared component associated with it will disappear. Some remnants may be user data, intentionally retained settings, shared components, or installer records that other software still needs. Treat a leftover as safe to remove only after confirming that the original app is gone, the artifact belongs to it, and no remaining application or Windows component still uses it.

• This program refuses to uninstall

  A program that will not uninstall may still be running, may have damaged or incomplete installer data, or may be in a partially removed state. Use the program's normal uninstall path first, then restart and repair or reset the app where supported. If removal still fails, use Windows' documented troubleshooting path or the vendor's uninstaller rather than deleting program folders or registry entries manually.

• Which background apps are actually slowing my PC down?

  Seeing many processes in Task Manager does not by itself mean that the PC is overloaded. The useful question is whether one or more background applications are consuming enough CPU, memory, or disk activity to interfere with the work you are doing. Measure the load first, then reduce background activity only for applications that are both unnecessary at that moment and materially using system resources.

• My PC showed a blue screen — what should I check first?

  A blue screen means Windows stopped because it detected a serious problem. One isolated crash does not automatically prove that hardware is failing, but repeated crashes with the same stop code deserve investigation. Record the stop code, look for recent hardware, driver, app, or Windows changes, and use matching evidence before deciding whether the problem is software, a driver, memory, storage, or other hardware.

• Bluetooth disappeared from Windows

  If the Bluetooth switch or icon has disappeared from Windows, first find out whether Windows can still detect the Bluetooth adapter. Airplane mode, a temporary hardware state, a missing or incompatible driver, firmware, or the Bluetooth hardware itself can all be involved. Restore the adapter first; pairing individual Bluetooth devices comes later.

• Why does my browser keep running after I close it?

  Closing the last browser window does not always stop every browser process. Browsers may intentionally keep background apps, extensions, notifications, synchronization, or startup-preloading components active. First confirm whether the remaining processes are expected and whether they are materially using CPU or memory; then change the browser's own background or startup setting before terminating processes or making system-level changes.

• "Camera is in use by another application"

  If Windows says another application is using the camera, first close programs that may still have a camera session open and test again. This is different from a missing camera or a general hardware failure: Windows can see the device, but another process or an access restriction may be preventing the current app from using it.

• Windows can't use my camera

  If the camera does not work, first separate three different problems: Windows cannot detect the camera, Windows detects it but reports a device problem, or an application is blocked from using it. Check physical camera controls and Windows detection first, then privacy access, and only change the driver when the evidence points to a device or driver failure.

• Windows says the drive must be formatted

  If Windows says a drive must be formatted before it can be used, do not format it while important files are still missing. The filesystem may be damaged even though some file data remains recoverable. Preserve the drive, check its hardware health, recover important data to another drive first, and only then attempt filesystem repair or reformatting.

• My PC/laptop is getting very hot

  A warm PC is not automatically overheating. Heavy work can make the processor, graphics hardware and cooling system produce more heat, but repeated shutdowns, strong performance drops, blocked airflow, or heat that makes the case unsafe to touch need attention. First reduce the workload and check airflow; if the problem continues while the PC is almost idle, investigate the cooling system or hardware.

• I accidentally deleted a file or folder

  A deleted file or folder may still be recoverable. Check the Windows Recycle Bin first, then any backup or cloud recycle bin that may contain another copy. If no protected copy exists, minimize use of the affected drive because new data can overwrite the space where the deleted file was stored.

• Windows says the drivers for this device are not installed (Code 28)

  Code 28 means Windows has detected a device but does not have a suitable driver installed for it. This is different from a device that is merely disconnected or one that has already reported a hardware failure. Start with Windows Update, then use the device manufacturer's official driver if Windows cannot find a compatible one.

• Windows stopped this device — Code 43

  Code 43 means that a driver controlling the device reported to Windows that the device had failed in some way. It does not by itself prove whether the underlying cause is the driver, the connection, power, or the hardware itself. Check recent changes and simple physical causes first, then repair or roll back the relevant driver if the evidence supports it.

• Windows says this device is not connected (Code 45)

  Code 45 means Windows has a record of the device, but the device is not currently present or connected. It is not, by itself, evidence of a bad driver or failed hardware. If the device is removable, reconnect it and check its cable, port, hub, and power. If the device should be permanently present but Windows still reports Code 45, investigate why Windows can no longer detect it.

• My C: drive is full — what can I safely remove?

  A nearly full C: drive can slow Windows and interfere with updates. The safest first targets are files Windows itself identifies through Storage Sense or Cleanup recommendations, plus personal files and apps you no longer need. Do not manually delete large Windows-managed files or folders such as WinSxS, pagefile.sys, or hiberfil.sys just because they use a lot of space.

• Do I actually need to update this driver?

  Not every old driver needs replacing. Windows installs recommended drivers automatically, while other driver versions may appear only as optional updates. A driver update is most useful when there is evidence that the driver is related to a real problem, a compatibility change, or a Windows security restriction.

• File Explorer became slow after I installed a program

  Some desktop applications integrate directly with File Explorer by adding context-menu commands, icon overlays, preview handlers, property pages, or other Shell extensions. If Explorer became slow, hangs, or pauses after a recent installation, that new integration is a useful clue but not proof of cause. Identify the exact Explorer extension and reproduce the problem before disabling or removing anything.

• The file exists but is corrupted or will not open

  A file that still exists but will not open should first be recovered from an intact older copy where possible. Check OneDrive or SharePoint Version History, File History, and application-specific recovery options before modifying the damaged file. Preserve the original, and investigate storage health if corruption affects multiple unrelated files.

• My files suddenly open with the wrong app

  Windows uses file-type associations to decide which application opens a given kind of file. If a file suddenly opens with the wrong program, first check and restore the default app for that file extension. A wrong default is different from a broken association: deeper repair is only needed when the intended app is no longer registered, no suitable handler is available, or the association points to software that is no longer present.

• I saved over the wrong version of a file

  If a file was saved over with unwanted changes, the best recovery path is usually an older version stored by OneDrive, SharePoint, File History, or the application itself. Do not keep editing the file until you have checked those sources. If no previous version or backup exists, Windows may have no intact copy of the earlier contents to restore.

• My files disappeared after OneDrive sync

  Files that disappear from File Explorer after OneDrive changes are not always deleted. They may still exist on OneDrive.com, belong to another Microsoft account, have been excluded from local sync, or be in the OneDrive recycle bin. Check the cloud copy first before resetting sync or attempting low-level file recovery.

• My files disappeared after a Windows update or profile problem

  Files that appear missing after a Windows update are not always deleted. Windows may have moved them, signed you into a temporary or different profile, retained them under Windows.old, or left them in OneDrive or an existing backup. Protect any work created in a temporary profile first, then locate intact copies before attempting deleted-file recovery.

• I accidentally formatted a USB drive or SD card

  Formatting a USB drive or SD card removes the normal file-system view of the files, but recovery may still be possible. Stop using the device, do not format it again, and recover files to a different drive. Windows File Recovery supports recovery after formatting and uses Extensive mode for FAT, exFAT, and formatted NTFS media.

• I lost a Word, Excel, or PowerPoint document

  A missing Office document may still be recoverable if Word, Excel, or PowerPoint closed unexpectedly, if AutoRecover retained a temporary version, or if the file was stored in OneDrive or SharePoint with Version History. Check Office recovery options before searching the disk or recreating the file.

• A partition disappeared from my drive

  If a partition disappears or its former space shows as Unallocated, do not create a new volume, format the space, or write new data there while important files are missing. The filesystem may still exist even though Windows has lost the partition entry that locates it. Preserve the disk, confirm its physical health, and recover data or the partition structure before reusing the space.

• Malware or ransomware damaged my files

  If malware or ransomware has deleted, encrypted, or corrupted files, remove the active threat before restoring data. Restoring files onto an infected device can allow them to be damaged again. After the device is clean, recover from a known good backup, OneDrive Version History, the OneDrive recycle bin, or a whole-OneDrive restore point from before the attack.

• Nobody can hear me in calls

  If nobody can hear you, first find out whether Windows can see the intended microphone and record sound from it. A microphone can be connected but muted, silent, blocked by privacy settings, not selected as the input device, or simply not selected inside the calling app even though Windows sees it fine. Prove which part of the capture path is failing before changing drivers.

• The internet works on other devices, but not this PC

  If phones or other computers can use the same network, the internet connection itself is less likely to be the problem. The fault is more likely somewhere on this PC: its network adapter, IP address, connection to the router, DNS settings, or a proxy or VPN. Check the failing layer before resetting the whole network.

• There is no sound from this PC

  If the PC produces no sound, first check whether Windows is sending audio to the intended output device and whether that device is muted, disabled, or missing. If Windows cannot see an output device at all, investigate device detection and the audio driver; if the device exists but audio still fails, check the Windows audio services before making broader system changes.

• Windows is trying to start a program that no longer exists

  Windows can be configured to launch applications automatically when you sign in through several startup mechanisms. If one of those registrations still points to an application file that is no longer present, the registration may be an orphaned startup entry. Confirm that the configured target is genuinely missing and that the application is no longer installed before removing only that specific startup registration.

• Do I need to update every program on my PC?

  A newer application version does not by itself tell you how urgent an update is. Updates can contain security patches, bug fixes, compatibility changes, or new features. First confirm that an update is genuinely available from a trusted source, then prioritize applications whose publisher identifies security or compatibility fixes, applications exposed to untrusted files or internet content, and software that is already malfunctioning.

• Documents sit in the queue and never print

  If documents remain in the Windows print queue, first determine whether the queue itself is blocked or the printer is unavailable. A stalled job can stop newer jobs from progressing, and the Print Spooler service manages that queue. Cancel stuck jobs first, restart the spooler if necessary, and only move to printer connectivity or driver troubleshooting when the queue is no longer the part that is failing.

• The printer says offline even though it is on

  “Offline” means Windows cannot currently complete communication with the printer; it does not necessarily mean the printer is switched off. Check the physical or network connection, the Windows print queue and Print Spooler, and for network printers whether Windows is still using the correct printer address. The repair is complete only when a test page or the original document actually prints.

• Windows says my PC is getting less stable

  A falling Windows reliability index means recent failures have reduced the system's recorded stability, but the score itself does not identify what is broken. Use the dates where the index drops and inspect the reliability events underneath them—such as application failures, Windows crashes, hardware problems, updates, or driver changes—to find the actual pattern.

• Why does this program keep starting by itself?

  A program that keeps returning after you close it may be started by Windows Task Scheduler rather than by the normal Startup apps list. Scheduled tasks can run at sign-in, at system startup, at a specific time, when the PC becomes idle, or after another system event. Identify the exact task, its trigger, and the action it runs before disabling anything.

• A Windows service keeps stopping

  If a Windows service repeatedly stops and starts again, the restart may be an automatic recovery action rather than the cause of the problem. Repeated Service Control Manager failures show that the service is not staying healthy; use the crash event, faulting process or module, dependencies, and recent changes to find the underlying failure instead of repeatedly restarting it.

• A Windows service is using a lot of CPU or memory

  A Windows service can contribute to a slow PC when the process hosting it uses sustained CPU, memory, or disk resources. First measure the resource pressure, then identify the exact service behind the process before restarting or changing anything. Do not disable a service simply because it is running or because its name is unfamiliar; services may provide Windows, security, hardware, network, update, or application functions that other components depend on.

• I used Shift+Delete or emptied the Recycle Bin

  Shift+Delete removes a file without moving it to the Windows Recycle Bin, and emptying the Recycle Bin removes the normal restore path. Recovery may still be possible if another copy exists in File History or OneDrive, or if deleted data remains on the local drive. If no backup copy exists, minimize use of the affected drive before attempting recovery.

• Is it safe to disable this startup app?

  Disabling a startup app normally stops it from launching automatically when you sign in; it does not uninstall the application. The decision should be based on whether you need the app immediately after sign-in, what function it provides, and whether Windows measures meaningful startup impact. Avoid disabling security, hardware, accessibility, or synchronization software without first understanding what functionality would be lost.

• My PC restarts or switches off by itself

  An unexpected restart means Windows did not complete a normal shutdown, but that fact alone does not identify the cause. Kernel-Power Event 41 can follow a Windows crash, loss of power, a forced shutdown, an unresponsive system, or some hardware failures. Use the bug-check data and the events immediately before the restart to narrow the cause instead of assuming the power supply or Windows itself is at fault.

• I never use this program — why is it always running?

  An application can keep running because it starts automatically, performs background work, or launches helper processes even when you rarely open its main window. Treat low recent use as a reason to review the app, not as proof that it is safe to remove. First identify what the app does and what resources it consumes; then choose between disabling startup, reducing background activity, or uninstalling it if you genuinely no longer need it.

• Windows Update error 0x80070002: a required file could not be found

  In a Windows Update incident, error 0x80070002 means Windows could not find a file required by the operation. The code does not identify which file is missing or why. Restart once and use the Windows Update troubleshooter first; if the error repeats, inspect the servicing evidence before resetting caches, repairing components, or changing system files.

• Windows Update error 0x80070005: access denied

  In a Windows Update incident, error 0x80070005 means the update process was denied access to a file, folder, registry entry, or other resource it needed. The code does not identify which resource blocked the update. Check the Windows Update and CBS logs and the surrounding evidence before changing permissions or disabling security software.

• Windows Update error 0x80070070: not enough disk space

  Windows Update error 0x80070070 means Windows does not have enough free disk space to complete the update. Free space on the Windows system drive first, then retry the update. Do not manually delete unfamiliar Windows system files to make room.

• Windows Update error 0x80072EE2: the connection timed out

  Windows Update error 0x80072EE2 means a connection attempt timed out. Windows Update could not reach Microsoft Update or another configured update source in time. Check the PC's network connection and whether its configured update source is reachable before resetting Windows Update components.

• Windows Update error 0x80073712: the Windows component store is inconsistent

  Windows Update error 0x80073712 means the Windows component store is in an inconsistent state. The component store contains files and metadata Windows uses to install and repair system components. Repairing that store with Windows' servicing tools is the appropriate next step; repeatedly retrying the same update usually does not address the underlying problem.

• Windows Update error 0x800F081F: Windows cannot find the repair files it needs

  Windows Update error 0x800F081F means Windows could not find the source files needed for a package, feature, or component repair. Windows can normally use Windows Update as a repair source, but policy, connectivity, or an unsuitable local source can prevent that. Do not download individual system files from third-party sites; use Windows' supported repair sources.

• Windows Update error 0x800F0922: an update installer failed

  Windows Update error 0x800F0922 means Windows servicing could not complete an installer or servicing command. Microsoft also documents this code in cases involving insufficient system-partition space, VPN or connectivity problems, permissions, and damaged servicing tasks. The code alone does not identify which cause applies, so use the failed update, CBS log, and system context before changing partitions or Windows permissions.

• Windows Update error 0x8024402C: the update server name cannot be resolved

  Windows Update error 0x8024402C means Windows could not resolve the name of the proxy server or update server it was trying to contact. The problem is usually in DNS, proxy configuration, local network connectivity, or—in a managed environment—the connection to the organization's WSUS server. Check connectivity and proxy settings before resetting Windows Update.

• The same Windows update keeps failing

  When the same Windows update fails repeatedly, the useful clue is the error code and the stage where the update stops. Different codes point to different problems, such as missing disk space, a restart that has not completed, damaged Windows servicing files, or a network or proxy problem. Identify that cause before resetting Windows Update or repeatedly trying the same installation.

• Windows upgrade error 0xC1900101: Windows rolled back after a setup failure

  Windows upgrade error 0xC1900101 is a generic rollback code. Microsoft says it usually indicates a driver compatibility problem, but the base code alone does not identify the exact driver or failure stage. Preserve the full error, including any second "extend" code, and use SetupDiag or Windows Setup logs before removing or replacing drivers.