I've used philips head screws and about the only thing I watch out for are ones that are too long.
Any PC shop should have thousands of these and won't cost much. About a dollar here.
Bob
Hi everyone, just wanted to install another hard drive on my desktop computer, but it seems it's not that easy to find the screws to mount the second hard drive(I just took out the drive from my external 3.5 hard drive which is though a bit bigger than the original one in the Dell PC), it needs 6-32 hex head screws p/n WN322 according to Dell, but I was wondering if any other screws will do the job? Any links, stores or specifications? Thanks for your responses!I live in UK in case someone recommends a store.

Chowhound
Comic Vine
GameFAQs
GameSpot
Giant Bomb
TechRepublic