ahhh white screen with scroll ball for last 10 minutes

My roommates computer just decided it didn't want to work anymore and it went to a completely white screen with 2 scroll wheels just wizzing away. If anyone knows how to reset it w/out erasing everything on the hard drive to its factory setting that would be great!
thanks in advance

Welcome to Mac Forums.
Firstly, if you can boot in safe mode (holding down shift while booting), back up your Mac with CCC or Superduper
Also, what Mac and version of OS, specs, etc?
Post back and then we can start troubleshooting.

We already tried booting up in safemood but it did not work, we just got stuck on that screen.

15-inch: 2.8GHz, Core 2 Duo, Version 10.6.2

ok... you can try booting either from disc 1 of 2 of the leopard install discs if thats what it came with, or the Snow Leopard install disc (either is ok) holding down C on bootup.
If you can get there, then select the language and continue to the menu bar>utilities>disk utility. Repair permissions, and then verify disk, and if errors come up, repair disk.
If all is good, then quit disk utility, and quit installer, and reboot.

This could do the trick!

sweet thanks we'll give that a try!

well now we are freezing when the grey apple symbol shows up

Try zapping the pram.
Boot holding down command + option + p + r keys together immediately after the chimes and keep holding down until third set of chimes sound.
Sounds like HD.
So... if at any stage you get it booted with any trouble shooting we try, be sure to backup onto an external HD while you can.
Time machine will save your Data but you will need a new HD to use your Mac, where as CCC or SuperDuper will create a bootable backup that you can still use your mac until you get a new HD, and transfer the data back.

I should add if you have access to another Mac, and the HD in the above Mac isn't a goner, then you can try to retrieve the data in Firewire target disk mode How to use and troubleshoot FireWire target disk mode
If the target HD doesn't show, then you can say goodbye to it unfortunately.