My pc will restart for no reason.

[IceMan00004]

It seems like when I've been using my pc for a while it will just restart for no reason. What might cause this and how can I fix it?
My system specs are:
p3 733
win 98
64mb geforce 3
dvd and cd-r drives

[Lance1]

Hi IceMan00004,

Temperature can be the primary cause, so check your power supply and all other fans in the case and make sure they’re in good order. Even a fan that is spinning slowly can’t generate the proper airflow to keep the components cool in the case.

Lance.