How to fix 0x800700aa error in Windows?

Error 0x800700AA means Windows needed a file, a drive, a service or an installer that something else was using at that moment. It is Win32 error 170, "The requested resource is in use." Restart once and retry, then follow the fix for the place where you saw the code.

Facts checked on 15 October 2026. Steps written for Windows 11 (25H2 and 26H2) and Windows 10 22H2.

What error 0x800700aa means in Windows

0x800700AA is a plain Windows system error in the eight digit form that Windows Update, Windows Security and File Explorer print. 0x8007 marks a Win32 error wrapped for these components. 00AA is 170 in hexadecimal. Microsoft's list of system error codes gives 170 the name ERROR_BUSY and the text "The requested resource is in use."

So the code does not say that anything is broken. It says that at one moment Windows asked for something and another process had it. What that something is depends on the window where you saw the code, and so does the fix.

Why error 0x800700aa happens, from most to least likely

Microsoft has not published one cause for 0x800700AA, because error 170 is a general code. The ranking below follows what the code means, where readers of this page meet it, and what Microsoft says about the KB5005292 package. Each cause points to its fix.

How to fix error 0x800700aa in Windows

Fix 1 takes five minutes and changes nothing, so everybody starts there. Fixes 2 to 5 each match one window where the code appears: pick yours from the table. Fixes 6 and 7 are for a code that keeps coming back.

Fix 1. Restart Windows, close what is running and retry

5 minutesNo riskAlways first, and above all when the code appeared once.

Error 170 means another process held the resource at that moment. A real restart ends every process, including installers and scans that were still running, so the next attempt finds the resource free.

1. Save your work and close your apps, including cloud sync and backup apps you can close.
2. Select Start > Power > Restart. Use Restart, not Shut down, because Fast Startup can keep parts of the last session.
3. After the restart, wait a minute so that startup tasks finish.
4. Repeat exactly what failed: Retry in Windows Update, the switch in Windows Security, the copy or the restore.
5. If it fails again, note the window and the exact text, then pick your fix in the table above.

Fix 2. Fix KB5005292 "Install error - 0x800700aa" by checking the Defender for Endpoint sensor version

10 minutesNo riskWindows Update or Update history shows "Update for Microsoft Defender for Endpoint - KB5005292" with "Install error - 0x800700aa". This is almost always a work or school PC.

KB5005292 updates the Defender for Endpoint EDR sensor, MsSense.exe. Microsoft writes that the update applies only if the sensor on the PC is older than the package. When the sensor is already at that version or newer, or the package is from another branch, the installer stops instead of replacing a sensor that is running.

1. In Settings > Windows Update > Update history, note the version in the failed update's name, for example 10.8838.26060.15013.
2. Right-click Start and select Terminal (Admin). On Windows 10, search for powershell and select Run as administrator.
3. Read where the sensor is installed. The folder name ends with its version number.

   Get-ItemProperty -Path 'Registry::HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows Advanced Threat Protection\' -Name 'InstallLocation'

4. Compare the version at the end of InstallLocation with the version from step 1.
5. If the installed version is the same or higher, the update is not needed. The failure is expected and you can leave it.
6. If the installed version is lower, restart (Fix 1) and select Retry once more.
7. If it still fails on a work PC, send the two version numbers to your IT team. A management server such as WSUS or Intune may offer a package from the wrong branch.

Fix 3. Turn on Microsoft Defender after removing the other antivirus

20 minutesLow riskWindows Security shows 0x800700AA when you turn on Microsoft Defender or real-time protection.

Windows runs one active antivirus at a time. While another antivirus is registered as active, or a badly removed one still leaves its parts behind, Microsoft Defender cannot take the antivirus slot and the switch fails with error 170.

1. Open Windows Security > Virus & threat protection. If it names another provider, that program is the active antivirus.
2. Remove that program in Settings > Apps > Installed apps (Windows 10: Settings > Apps > Apps & features). Its steps are here: Uninstall a program or app in Windows.
3. If the maker offers its own removal tool, run it too. Antivirus programs often leave drivers and services behind.
4. Restart with Start > Power > Restart.
5. Open Windows Security > Virus & threat protection > Manage settings and turn Real-time protection on.
6. Under Virus & threat protection updates, select Check for updates so that Defender gets current security intelligence.

Fix 4. Find the program that holds the file or drive, then copy or delete again

10 minutesLow riskFile Explorer shows 0x800700AA when you copy, move, rename or delete a file, a folder or a whole drive.

Here error 170 means another program has the file, the folder or the drive open. Resource Monitor shows which process holds a file, so you close that one program instead of guessing.

1. Close every app that may use the file: the app that made it, a media player, a preview window, a sync or backup app.
2. Press Win + R, type resmon and press Enter to open Resource Monitor.
3. Open the CPU tab and expand Associated Handles.
4. Type the file or folder name, or the drive letter such as E:\, in the Search Handles box.
5. Note the Image column: that process holds the file. Close that program normally.
6. If it does not close, end it in Task Manager. Unsaved work in that app is lost. Steps: Close a frozen app (Task Manager, Force Quit).
7. If the image is explorer.exe, close every File Explorer window or restart it with Restart File Explorer.
8. Retry the copy, move or delete.

Fix 5. Run System Restore from Windows Recovery and pick another restore point

30 minutes to 1 hourRead the warningSystem Restore stops with 0x800700AA and says it did not complete.

System Restore replaces system files, drivers and programs. If a running program or a backup holds one of them, the restore stops with error 170. In Windows Recovery none of your programs run, so nothing holds the files.

1. Open Settings > System > Recovery and select Restart now next to Advanced startup. On Windows 10: Settings > Update & Security > Recovery.
2. Select Troubleshoot > Advanced options > System Restore, then pick your account and type its password.
3. Select Choose a different restore point and Next.
4. Tick Show more restore points and pick a point from before the problem began.
5. Select Next and Finish, and wait. The PC restarts on its own.

The full steps, including System Restore from inside Windows, are here: Undo recent changes with System Restore.

Fix 6. Find the startup program that holds the resource with a clean boot

20 minutesLow riskThe code comes back after every restart, in Windows Security, in file operations or in Windows Update.

A clean boot starts Windows with only Microsoft services. If the action works now, a third-party program that starts with Windows held the resource: a backup tool, a sync client, a disk tool or a security program.

1. Open System Configuration. Select Search on the taskbar, type msconfig and select System Configuration from the results.
2. Hide Microsoft services. On the Services tab, select the Hide all Microsoft services check box. Only services from other companies stay in the list.
3. Disable the remaining services. Select Disable all, then select Apply.
4. Open Task Manager. On the Startup tab of System Configuration, select Open Task Manager.
5. Disable the startup apps. On the Startup apps tab in Task Manager, select each item whose status is Enabled and select Disable. Write down or take a screenshot of the items you disable: you need the list to turn them back on.
6. Confirm the changes. Close Task Manager. On the Startup tab of System Configuration, select OK.
7. Restart and test. Restart the PC. Windows now starts in a clean boot environment: try again the thing that failed (run the app, install the update, uninstall the program).

These steps were written for Windows 11 25H2 and 26H2. The full page with the other versions and what each result means: How to perform a clean boot in Windows

1. In clean boot, repeat the action that failed with 0x800700AA.
2. If it works, turn half of the disabled services back on and restart.
3. Repeat with halves until the code returns. The last group you turned on holds the program.
4. Update, reconfigure or remove that program, then undo the clean boot with Enable all.

Fix 7. Repair Windows system files with DISM and SFC

30 minutesLow riskFixes 1 to 6 did not help, or other Windows errors appear as well.

A damaged system file can make a Windows component such as the update installer or Windows Security hang while it holds its files. DISM repairs the component store, then SFC repairs the files from it.

1. Open an elevated command window. Right-click Start and select Terminal (Admin), or type cmd in the search box, right-click Command Prompt and select Run as administrator. Select Yes when Windows asks for permission.
2. Run DISM first. Type the command below and press Enter. DISM downloads clean copies of damaged components from Windows Update, so it can take several minutes. Wait until it says The operation completed successfully.

   DISM.exe /Online /Cleanup-Image /RestoreHealth

3. Run System File Checker. In the same window, type the command below and press Enter. Do not close the window until the verification reaches 100%.

   sfc /scannow

4. Read the result and restart. Compare the last message with the table below this guide, then restart the PC so that repaired files are loaded.

These steps were written for Windows 11 24H2 and 25H2. The full page with the other versions and what each result means: Run DISM and SFC to repair Windows system files

1. When both commands finish, restart with Start > Power > Restart.
2. Repeat the action that failed with 0x800700AA.

If error 0x800700aa is still there: what to check and send

Error 170 is always about one resource held by one process. Write down where you saw the code before you ask for help, because the right person to ask depends on it.

• On a work PC: Defender for Endpoint, Windows Update and security settings are usually managed by your company. Send the details above to your IT team instead of changing policies.
• When it is hardware: if file operations on one drive fail with several codes and the drive disconnects or makes noise, back it up and test it with Check a disk for errors (chkdsk). Error 170 itself is not a disk fault.
• A related code: if a file cannot be decrypted while you copy it, see our guide to error 0x80071771.

How to keep 0x800700aa from coming back

The code comes back when two programs want the same thing at the same time. A few habits keep that from happening.

• Keep one antivirus. Two security programs fight for the same slot and the same files.
• Remove an old antivirus with its maker's removal tool, not only from Installed apps.
• Close sync and backup apps before you move large folders, and let a running backup finish before System Restore.
• Restart with Start > Power > Restart at least once a week, so that installers and updates finish.
• Eject USB drives with Safely remove before you unplug them.
• Windows 10 left support on 14 October 2025. A Windows 10 PC without Extended Security Updates gets no new monthly updates, so plan the move to Windows 11.

Frequently asked questions

What is error 0x800700aa?

It is Win32 error 170 in the eight digit form Windows Update, Windows Security and File Explorer use. Microsoft names it ERROR_BUSY, with the text "The requested resource is in use." It means another process was using what Windows needed at that moment: a file, a drive, the antivirus slot or an installer. It does not mean that a file is damaged. A restart clears it in many cases, and the window where you saw it tells you which fix to use next.

Is 0x80070aa the same error as 0x800700aa?

Yes, in practice. 0x80070aa has one zero missing and is a common typo of 0x800700AA, which is how many people search for it. Windows always prints the code with eight digits after 0x. The same goes for 800700aa without 0x, ox800700aa with the letter o, and error 170. All of them mean "The requested resource is in use." Use the fixes on this page.

Why does KB5005292 fail with install error 0x800700aa?

KB5005292 updates the Microsoft Defender for Endpoint EDR sensor, MsSense.exe. Microsoft writes that the package applies only when the sensor on the PC is older than the package. If the sensor is the same or newer, or the package is from another branch, the install stops with 0x800700AA. Check the installed version with the PowerShell command in Fix 2. If it is current, the failure can be ignored. On a work PC, IT manages this update.

Can I ignore the KB5005292 install error?

Often, yes. If the installed sensor version is the same as or newer than the version in the update name, the update has nothing to do and the failure is expected. Microsoft releases this update again and again under the same KB number, so a newer one will replace it. If the installed sensor is older, do not ignore it: the sensor protects the PC. Restart and retry, then ask IT.

Why can't I turn on Microsoft Defender with error 0x800700aa?

Usually another antivirus is still active, or was removed without its maker's removal tool. Windows runs one active antivirus at a time, so Microsoft Defender cannot take the slot while the other one holds it. Check Windows Security > Virus & threat protection for another provider, remove it, restart and turn real-time protection on. Fix 3 has each step. On a work PC, a policy may manage Defender instead.

Should I turn off my antivirus to fix 0x800700aa?

No. Turning off protection is not a fix for this code. If a second antivirus is the cause, remove it and use one antivirus, as Fix 3 shows. If a security program holds a file you copy, close or update that program instead. For a single test, you may pause protection for a few minutes and turn it back on right after: Turn off Microsoft Defender protection for a moment. Never keep it off.

Does Disk Cleanup or freeing space fix 0x800700aa?

Not on its own. Error 170 means a resource is in use, not that the disk is full. A full disk gives another code, 0x80070070, "There is not enough space on the disk." Keep enough free space for updates and restore points, but start with the fix for the window where you saw the code. Disk Cleanup does not close a program that holds a file.

I see 0x800700aa in an Xbox app, a backup tool or a repair tool. Is it the same?

It is the same error, a resource that another process was using, but the fix depends on the program. A backup tool that cannot connect to its server with 800700aa usually means the target or its service is busy with another job. A repair tool that cannot start may find another repair or installer running. Restart, close other installers, and retry. This page covers the Windows cases in detail.

What does the error mean in other languages, for example インストール エラー or erro 0x800700aa?

The meaning is the same in every language version of Windows: the requested resource is in use. The Japanese "インストール エラー - 0x800700aa" is the same install error that Windows Update shows next to KB5005292 in English. The fixes and commands on this page work the same in any language of Windows. This page is in English only.