every time i use gnotella, my computer restarts on it's own after about five minutes of gnotellage. wtf is going on here?

Which operating system are you running?

i run windoze 98 se, of course

Since Gnotella can use quite a lot of resources, try to cut out a few programs running in the background before you start Gnotella, by pressing Ctrl+Alt+Del, and End Task for some of them which you know you don't need running at the moment, see if that helps.