Photoshop warning

[Rodge2]

I have just installed Photoshop on my computer. It's an old one that I've had for years but worked fine on my previous computer. It seems to be functioning correctly, but when I started it up, it gave me a warning:
'You currently have Adobe Photoshop's primary Scratch & Windows primary paging file on the same volume, which can result in reduced performance. It is recommended you set Adobe Photoshop's primary scratch volume to be on a different volume, preferably on a different physical drive.'

I've had a look at the folders for Photoshop but can't identify anything that looks like a primary scratch file, so not sure what to do to rectify this, or if I really need to. Any help appreciated. Thanks. Oh, I'm running Windows XP SP2.

[Fanriffic]

Have a look at the following link which might help to explain Scratch Disks in Photoshop and how to set it up:

http://bit.ly/hNNusm

It's just a warning telling you that you need to allocate some of your PC memory (virtual memory) to photoshop so it will run better.