Fixing TYPE_E_CANTCREATETMPFILE (0X80028CA3) Error

The temp folder is full or corrupted

This is the #1 cause. I've seen it hundreds of times. The %TEMP% folder gets stuffed with junk — leftover installers, crash dumps, old logs. Once it hits a certain size (usually around 2 GB on older systems), Windows can't create new temp files. You'll get TYPE_E_CANTCREATETMPFILE error code 0X80028CA3.

How to clean it

1. Press Win + R, type %TEMP%, hit Enter.
2. Select all files (Ctrl + A), then delete (Delete key). You'll get some "file in use" errors — just skip those.
3. Empty the Recycle Bin.
4. Run Disk Cleanup as admin: cleanmgr in Start menu, select your system drive (usually C:), check "Temporary files", let it run.

If you have more than 500 MB in the temp folder, that's often the trigger. Don't bother with third-party cleaners — Windows Disk Cleanup does the job fine.

Temp folder permissions are wrong

Sometimes the temp folder's permissions get messed up, especially after a Windows update or if you moved your user profile. The user account running the app (often a service account for IIS or SQL Server) needs full control over %TEMP% and C:\Windows\Temp.

Check and fix permissions

1. Open File Explorer, navigate to C:\Users\\AppData\Local\Temp.
2. Right-click the Temp folder, select Properties.
3. Go to the Security tab. Click Advanced.
4. Make sure your user account has "Full control". If not, click Change permissions, then Add.
5. Type your username, check "Full control", OK out.

For C:\Windows\Temp, you need SYSTEM and Administrators groups set to full control. Don't add random users — keep it tight. If you're getting this error in IIS or a Windows service, check that the application pool identity has write access to C:\Windows\Temp.

Disk space is critically low

Less common but happens. If the system drive (usually C:) has less than 1 GB free, Windows sometimes refuses to create temp files. This error pops up in Office apps (Word, Excel), VBA macros, and COM automation scripts.

Free up disk space fast

1. Run cleanmgr as admin. Click "Clean up system files" — that gets rid of Windows Update leftovers.
2. Check %TEMP% again — if you skipped files earlier, try deleting them in Safe Mode.
3. Move large files (videos, ISOs) off the system drive.
4. Run chkdsk C: /f if you suspect disk corruption — rare but possible.

You need at least 5-10% free space on the system drive for Windows to breathe. Under that, strange errors happen.

Environment variables got mangled

I've seen this in companies that push broken GPOs. If TEMP or TMP environment variables point to a non-existent folder, this error shows up. For example, %USERPROFILE%\AppData\Local\Temp should work — but if a GPO sets it to D:\Temp and that drive doesn't exist, you're stuck.

Verify the variables

1. Open Command Prompt, type echo %TEMP% and echo %TMP%.
2. If they point to a folder that doesn't exist, create it (e.g., md D:\Temp).
3. Or fix via System Properties: Right-click This PC → Properties → Advanced system settings → Environment Variables.
4. Under User variables, set TEMP and TMP to %USERPROFILE%\AppData\Local\Temp.
5. Restart the app or your machine.

Don't set these to a network path — it'll slow everything down and cause more errors.

Quick-reference summary table

Start with the temp folder cleanup. 9 times out of 10, that's all you need. The other fixes are for edge cases — but they do come up. If none of these work, run sfc /scannow to check for system file corruption, then DISM /Online /Cleanup-Image /RestoreHealth. Still stuck? You might have a deeper profile issue — recreate the user account.