Is it safe to delete crash dump files and Windows error reports?

Yes, you can delete crash dump files and Windows error reports. Windows doesn't need them to run. They exist so you, Microsoft or an app developer can find out why something crashed. The one exception: if your PC is getting blue screens right now, keep the latest dumps until the problem is solved.

Quick verdict:

• Safe to delete: %LocalAppData%\CrashDumps, C:\Windows\MEMORY.DMP, old files in C:\Windows\Minidump, and error reports in C:\ProgramData\Microsoft\Windows\WER.
• Keep for now if you're troubleshooting crashes or a support team asked for a dump.
• Use Windows' own tools for the files in C:\Windows and ProgramData\Microsoft. Disk Cleanup and Settings handle them safely.

What are crash dumps and error reports?

A dump file (.dmp) is a snapshot of memory taken when something crashes. A debugger such as WinDbg can open it and show which driver or program caused the crash. An error report is a small package Windows Error Reporting (WER) prepares to send to Microsoft, sometimes with a dump inside.

They live in several places:

MEMORY.DMP and Minidump

When Windows stops with a blue screen, it writes a dump before restarting. Microsoft's memory dump file options page lists the defaults: the full or kernel dump goes to %SystemRoot%\Memory.dmp, and small dumps to %SystemRoot%\Minidump. A new MEMORY.DMP overwrites the previous one, while small dumps are kept as a history. Modern Windows uses the Automatic memory dump setting, which contains the same data as a kernel dump.

On home PCs, Windows may delete a large MEMORY.DMP on its own when free space is low. Microsoft described this behaviour when it was introduced in Windows 7.

CrashDumps

%LocalAppData%\CrashDumps is the default folder for app crash dumps when Windows Error Reporting is set up to keep them locally. According to Microsoft's documentation, that feature is off by default, keeps up to 10 dumps, and replaces the oldest when it's full. Some apps and installers turn it on for themselves, which is why you may find this folder filled with .dmp files named after a program that crashes often.

WER reports

C:\ProgramData\Microsoft\Windows\WER holds reports in ReportArchive (already processed or sent) and ReportQueue (waiting to be sent). If a report can't be sent, the queue can grow.

How much space does it use?

The built-in way: open Settings → System → Storage → Temporary files. Look for Windows error reports and feedback diagnostics and, after a blue screen, the System error memory dump files entries. Classic Disk Cleanup shows the same items once you click Clean up system files.

For CrashDumps: paste %LocalAppData%\CrashDumps into File Explorer, select everything and press Alt+Enter to see the total.

With SquirrelDisk: scan C: and you'll see where the big files are. If MEMORY.DMP is large, it shows up as a slice inside Windows. You can also click A folder and paste %LocalAppData% to look at CrashDumps. SquirrelDisk runs without admin rights, so some system folders, including parts of WER, may show smaller than they really are.

How to delete it safely

With Settings or Disk Cleanup (recommended)

1. Open Settings → System → Storage → Temporary files.
2. Tick Windows error reports and feedback diagnostics, and System error memory dump files / System error minidump files if they're listed.
3. Untick anything else you're not sure about, especially Downloads.
4. Click Remove files.

In Disk Cleanup, choose Clean up system files first, otherwise the dump entries don't appear.

You can also clear old reports from Reliability Monitor: search for "View reliability history" in Start, click View all problem reports, then Clear all problem reports.

CrashDumps by hand

1. Close the app that was crashing.
2. Open %LocalAppData%\CrashDumps.
3. Delete the .dmp files. You can delete the whole folder; it's recreated when needed.

SquirrelDisk can do this too: drag CrashDumps into the collector and choose Move to Trash. It asks for an extra confirmation because the folder is in AppData. It won't delete MEMORY.DMP, Minidump or anything in C:\ProgramData\Microsoft, because it never deletes inside C:\Windows or Windows' own ProgramData folders. Use Settings for those.

When to keep them

Deleting dumps doesn't break anything, but you lose evidence. Keep them if:

• Your PC is blue-screening. The newest file in C:\Windows\Minidump usually names the driver that failed. Anyone helping you on a forum or at a repair shop will ask for it.
• An app keeps crashing and its developer asked you for a dump. Send the newest file from CrashDumps.
• You're testing a fix, such as a new driver. Keep the old dumps until you're sure the crashes are gone.

Once the problem is solved, delete them.

How to stop them growing back

The real fix is to stop the crashes: update drivers, check the app that keeps failing, run Windows Update. If space is still tight:

• Use small dumps. Open Settings → System → About → Advanced system settings. Under Startup and Recovery click Settings, and set Write debugging information to Small memory dump. That avoids a multi-gigabyte MEMORY.DMP. You need to restart for it to apply.
• Turn on Storage Sense under Settings → System → Storage so Windows cleans temporary files on a schedule.

For other files that pile up in the same places, see is it safe to delete temp files and ETL files.