quitting 2004 automatically restarts my PC...

gents, I just installed 2004 last night. everything went fine, but when I went to quit the program, my computer automatically rebooted. when I tried to run 2004 again, it wouldn't run unless I had CD 4 in the drive. When I put it in, I got the 2004 splash screen, and nothing else. it just hung. I uninstalled it, reinstalled it, and the same thing happened. first time is fine, then when I quit, the reboot, then nothing. FS2002 still runs fine. I did notice that my machine seems slow when the desktop shortcuts come on after the reboot. I'm no PC whiz by any stretch of the imagination, so I'm not sure where to start. anyway, if you have any ideas....mjbXP2100ram: 1 gigHD 110 gigasus MBwin XPTi 4400 128mb