Random Freezes

Hi, I recently moved my computer from one house to another. Before, it was working perfectly fine, but after moving it and setting it back up yesterday, it's frozen twice. Both time I had multiple tabs open in Mozilla, loading pages, and had music playing in Windows Media Player. When it froze, all sound stopped, the screen was frozen and I couldn't move the mouse or enter any keyboard commands, and I was forced to shut it down manually.

I'm hoping it's just a freak occurance, but if anyone knows anything I should check for or test for to try and fix it, I would greatly appreciate it. I'll let you know if it happens again. I have Windows 7 Professional 64-bit edition, let me know if you need any more information.

 

how old is it?

I would check temperatures with speedfan

 

Is it plugged in to a power strip or UPS? Is the wiring in the new house very old?

 

I think I've narrowed it down to my internet. I've got a wireless USB virgin broadband modem (cause I'm in a rental house that doesn't have a phone line), and each time I've frozen, I've been online connected to it. It happened a third time earlier, and I unplugged the modem for a couple of hours and nothing bad has happened.

Temperatures have never risen above 55 degrees celcius, I don't think it's a wiring/power problem (but the house is kinda old), and I checked every component was properly plugged in and nothing fell loose during transition.

So, I'm awaiting reply from Virgin to see if they have any fixes.