You don't need to do this manually.
You can purge the scratch disk:
You will lose your history if you do this (all undos).
Basically you are running out of room on the system drive - not a good situation. I would talk to your friend about perhaps archiving some files and then deleting them. Or, buy a firewire drive and use that as a scratch disk.
Don't delete your friend's files if you want to remain friends.
that was nice and easy - seems to be doing the trick. thanks!
Purging the files has worked for a while up til now, but it seems to be only a very temporary fix. After purging I can work in Photoshop for a little while, then I soon get another warning about the scratch disk being full despite that I've also moved/deleted tons of files from the hard drive and emptied the trash to clear up space. and I often get the warning popping up as I'm opening a file so there's nothing yet to purge..
Is there ANYTHING else I can do to clear up scratch disk space?? I assumed that deleting files would clear up the most space but sometimes it doesn't even help and i still get the warnings..
Reducing the number of history states can help, but not always (depends on your work style).
If you keep running out of disk space, the only real option is to get more disk space.
Unfortunately, offset still works only in pixels, not in physical units.
(and someone broke the drag preview, darnit)