Error Message Help.

Every time I try to do a certain action/tool it gives me this message:

"Could not do *tool action* because scratch disks are full"

What does this mean? How do I fix it?

Photoshop uses your spare Hard Drive space as memory to help it perform tasks. If you monitor your free space while using Photoshop, you'll see it shrink depending on the number and size of files you have open, among other factors, then return to normal when you Quit.
You need more hard drive space, so burn some CDs and get rid of seldom used files to free up more space. Or you could buy another few Gigabytes in the form of a second Hard Disk. Then, in Photoshop, specify that new Drive as a Secondary Scratch Disc. Do this by choosing Preferences: Plug-Ins & Scratch Discs.

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