I do not know about you, but when your hardware explodes and your computer crashes it sends lightening bolts of pain through my veins. We have multiple computers in my house, and we have a lot of people living here so we really do need the computers!
Computer #1 for some time had reoccurring video problems, all of which seemed to be related to watching Netflix movies and Microsoft's Silverlight plugin. This changed and then the computer stopped booting. I pulled out the card and sure enough it was loaded with dust, although I had cleaned it recently it was enough to cause it to overheat. The capacitors, located above the fan/heatsink and at bottom right of photo, small silver circular things, exploded and they zapped the motherboard. We ran some checks, unplugged everything, memtest86+ and all, and we're confident that it's just the motherboard.
Computer #2 crashed a couple of days later while Dad was scanning. His was not really easy to determine either. However, after removing the motherboard completely we did realize it had some capacitors which looked fried and it was 5+ years old... We bought a new motherboard, processor, memory, hard drive and copy of Windows 7, so it's basically heaven now. We have even gotten him set up on dual screens in his office so he can really have a good time multi-tasking to his heart's desire. Sweet.
Words of warning? Occasionally de-dust your computer, or you'll probably mess it all up. Sure I looked occasionally but sometimes it's just not enough. Also, if you're upgrading to Windows 7 you can count on your older printer not working, and probably your scanner too. I will post soon about how you can get around your printer woes by being smarter than your hardware :) I hope you've enjoyed this post of Nerds R Us and we'll continue with the regular cultural updates in the near future!
Wikipedia: Capacitor Plague.