Why you're seeing this
Photoshop's scratch disk is space on your hard drive it uses as virtual memory. When you work on large files (multi-layer PSDs, panoramic stitches, 16-bit images), it fills up fast. On a typical Windows 10 PC, the default scratch disk is your C: drive. If that drive has less than about 10% free space, boom – you get the error.
The culprit here is almost always a combination of: a low free-space C: drive, leftover temp files from previous edits, and Photoshop not cleaning up after itself. Let's fix it in stages.
30-second fix – Clear Photoshop's temp files
Don't bother restarting your computer yet. Do this first:
- Close Photoshop entirely.
- Open File Explorer and paste this into the address bar:
%temp%\Adobe\Photoshop - Select all files (Ctrl+A) and delete them. If you get a file-in-use error, skip that file.
- Empty your Recycle Bin.
That removes Photoshop's temp scratch files. These are big binary blobs it creates during editing. I've seen this free up 50GB+ on some workstations.
Restart Photoshop. If the error's gone, you're done. If it comes back after a few minutes of work, move to the next step.
5-minute fix – Move the scratch disk to another drive
If you have a second internal or external drive (SSD preferred), move the scratch disk there. It'll also speed up Photoshop significantly – scratch disk I/O is a bottleneck on mechanical drives.
- Open Photoshop. Go to Edit > Preferences > Scratch Disks (Ctrl+K on Windows).
- Uncheck the C: drive. Check your D: or E: drive (or an SSD). If you don't have a second drive, you can use a fast USB 3.0 flash drive – but it's not ideal.
- Click OK, then restart Photoshop.
Pro tip: Don't use a network drive or a cloud-synced folder (OneDrive, Dropbox). Photoshop writes to scratch disk constantly, and sync services will fight with it, causing lag and corruption.
This fix works for 90% of users. If you're still getting the error after moving it, the scratch disk you chose might be too small itself – or you have a crazy large file.
15-minute fix – Clean up your system like a pro
Okay, you've tried the above and the error persists. Now we get surgical.
Step 1: Trim Windows temp files
Run Disk Cleanup on your C: drive. Type 'Disk Cleanup' in the Start menu, select your C: drive, and let it scan. Click Clean up system files – this gets the Windows Update cache, old Windows.old folders, and temp files. You can often reclaim 5-15GB.
Step 2: Manually kill stray Photoshop processes
Sometimes Photoshop leaves ghost processes running after you close it. Hit Ctrl+Shift+Esc to open Task Manager. Look for Photoshop.exe or AdobeIPCBroker.exe. End those tasks. Then delete the temp folder again from the first step.
Step 3: Disable 'Background Save' and 'Auto Recovery'
These features are useful but aggressive. In Photoshop, go to Edit > Preferences > File Handling. Uncheck Save in Background and set Automatically Save Recovery Information to Every 15 minutes (up from 5 or 10). This reduces write pressure on the scratch disk.
Step 4: Check your file size
If you're working on a PSD over 2-3GB, Photoshop will need 5-10GB of scratch space. Add that to your available free space. If your scratch drive has less than 20GB free, you'll hit this error again. Move the file to a larger drive or use Save As to a different location.
Step 5: Reset Photoshop preferences
Last resort – preferences can get corrupted. Hold Ctrl+Alt+Shift while launching Photoshop. Click 'Yes' when asked to delete the Adobe Photoshop Settings file. This resets everything – toolbars, scratch disk settings, panel layouts. You'll need to re-move your scratch disk (from step 2).
When to give up and buy hardware
If you're consistently hitting this error with large files and a modern system, you need more RAM or a dedicated scratch drive. Photoshop on Windows 10 uses scratch disk as RAM overflow – more RAM (32GB+) means less scratch. A dedicated NVMe SSD as a scratch disk is the nuclear option. I've seen that turn a 5-minute save into 30 seconds.
But for 99% of cases, the temp file cleanup and moving the scratch disk off C: will fix it. Don't waste time on registry tweaks or third-party cleaners – they rarely help here.