computer freezes randomly.

[JoPh]

could my video card overheating randomly freeze my pc?

i have geforce2 ultra. and the fan on it is broken.

is this definitaly the problem?

i just put a new heat sink on it.

 

[nboy22]

I would get a new fan on it, but it depends on how high the ambient room temperature is, and if you do anything like gaming with it that puts more load on it.

 

[SickBeast]

If your videocard is overheating, it will typically produce artifacts which are extremely noticeable. That said, if your system was stable before you changed the HSF on it, then that's the most likely culprit. Are you certain that you installed the new heatsink correctly? So hold on, the fan on the new heatsink is non-functional? Of course you need a fan on there. Get a VGA silencer; you'll be able to use it on a new card also if you ever upgrade.