I'm a new user of windows 7 64 bits, and when i'm playing quake 3, or defrag, the game is bugging after 5 minutes, without any error message. This is very annoying, can someone help me please?
Don't install q3 in Program Files or Program Files (x86) folders. They have all sorts of weird read/write permissions associated with them that will mess some stuff up for q3 (even simple stuff like opening your config in notepad to make a change). I have mine on my desktop but anywhere on your C drive or other hard drive outside of those 2 folders should be fine.
Then right click on quake3.exe and go to Properties. Click on the compatibility tab.
Check Run in Compatibility Mode and select Windows XP (Service Pack 2). (SP3 prob works fine too)
Also Check:
Disable Visual Themes
Disable Desktop Composition
Run Program as Administrator
Apply those settings and try it out. If you still have problems post it here but that should hopefully fix it for you.