Overclock problem on windows 7 64bit..?

This just proves your original overclock actually wasn't stable.

Shouldn't really make much difference whether 32 or 64bit either the system is stable or it isn't but that problem isn't unheard of.

My guess is that your margin for stability is borderline so you need to make the over clock more stable.

The fact that it runs stable at stock proves this and that it is not related to the 64 bit OS.

Most over clocking instability stems from a too higher frequency or latency for the memory or not enough ram volts. set your memory to it's max rated volts and set latency to 5,5,5,18 if DDR2.

Even if you have higher than 6 Gb can cause problems with over clocks.

It is difficult to offer you a solution because you do not mention what your hardware is.

Use memtest 86 on a bootable cd to test the memory stability first.

32-bit on sixty 4-bit processor has no longer something to do alongside with your overheating. at idle 60 ranges C is lots too extreme.. until eventually that's a P4. once you're saying fan, i'm assuming you imply the heatsink and fan? you does no longer use thermal grease on the fan by myself, the grease is to habit the warmth into the heatsink which the fan pulls/pushes air over to kick back. you % the layer of thermal grease to be as skinny as plausible (ideally some microns) collectively as nonetheless offering touch between the processor warmth spreader and the heatsink base. different than that, clean out any case followers, filters etc, tidy up any cables that would hamper the airflow into the heatsink. particularly supply your equipment a sturdy clean in case you will be stricken then set your motherboard up on a bench as this might do away with maximum skill airflow issues. if none of those artwork then have you ever overclocked or raised the voltages lots? if so then return them to inventory and spot if that helps

64-bit of course, uses more processing power, higher temps, you're overheating and possibly melting your components. Stop. Its as simple as that, your PC running 64-bit processes can not handle being overclocked.

Have you ever used programs like speedfan? That monitor your CPU's temperatures? And not the BIOS. They're wrong a lot.

If not, you really shouldn't even consider overclocking, as only experts should try it.