Mac Mini Computer Crashing

Question

Yesterday, I was kind of annoyed because my computer was running slower than usual, but it wasn't really getting in the way. Today, I logged out of an account on my mac mini, and I when I got to the login screen, the computer froze. So, I restarted the computer, and it took like 5 miniutes to load. When it finally did load, the login screen was bleached white and the mouse and keybord weren't responding. So, I tapped the power button to put it to sleep, and then tapped it again to wake it up. The screen was no longer bleached white, but the mouse and keyboard still weren't responding. So, I unplugged and replugged them, and I could move the mouse around the screen, but I couldn't click on anything. Again, I restarted the computer, this time with the Mac OS X install CD while holding down the C key, but nothing happened (it just stayed at the apple loading screen). I tried holding down F when I restarted again, and the hardware test said everything was fine. This time, I held down the mouse button, which ejected the CD. Then, I but it back in, and restarted. Again, nothing happened.
My install CD is not broken, and my mouse and keybord aren't broken, so I'm not sure what's wrong.
After I typed this, the computer successfully turned on, and auto-logged on to my brother's account. From there, I ran a disk utility verification, which told me that the disk was fine. Satisfied, I logged out of the account to log on to mine, and the same problem happened (the screen is now blue). This has happened multiple times now after a few restarts.
Any ideas?

Answer 1

try _*Resetting your Mac's PRAM and NVRAM*_.
if still no joy, try booting in _*safe mode*_.
JGG