Thanks for the info, Rey... but you almost gave me a heart attack when I tried this and changed my scratch disk to another partition. I later tried to open up Photoshop with the error saying that it cannot open photoshop because the file is locked, then photoshop would crash. Not knowing what caused this, I looked up the error message online. For a second there, I thought I might have to reinstall Photoshop. This link describes what also happened to me, and how to delete the preferences file:

http://photoshophelp.blogs.com/photoshophelp/2005/10/eileen_writes_p.html

my scratch drive is 28.8 gig (30 gig drive)

That's fine. It all depends on what size files you work on and how many
layers and effects you use. Most of your PS crashes are
because of lack of scratch disk.

I dont really crash much, rare in fact. I do save a lot, and i mean a lot. the millipede produced some 13 psd files, the largest of them being 52 megs.
i do a few larger things, making brushes are usually large. the millipede, i started him out at around 4000 x 2000 then brought him down.

This is something i will have in mind when i build my next desktop... PS will get its own drive, larger than the one it has now. the 30 gig is one I put in this computer for PS about a month ago due to PS crashing on me from a smaller main drive on an os I was testing out.

I have 4 gig of ram, windows vista (main) 7 64 bit(testing on a 40 gig drive) which is why the extra 30 appeared. i could only open 5 photoshop projects, didnt matter how big or small they were.. it would give me an error when i tried to open 6.. " Due to your settings or restrictions, photoshop cannot open this project" or something to that nature..