Hi. I built my computer about a year or two ago and have slowly been upgrading parts. The most recent of addition parts have been in place for at least 6 months. I run an updated version of Vista Ultimate with all avilible service packs. Today a few of my broswers were crashing on me so I decided it would be a good time to clean the dust out of my pc. The only tools I used were cotton q-tips with no liquids whatsoever. I did the following things in the exact order specified. First took out the cpu heatsink and cleaned all the dust out of it, then i removed the cpu and cleaned up the outline of dust it left on the motherboard. I carefully inspected the bottom side of the cpu and the pins on the motherboard facing up to makecontact with the many small circles on the bottom of my cpu. Everything seemed to be in order and I didn't notice any bent or discoloration of the pins or the cpu itself. I then removed both sticks of dual channel ram I have and dusted those off. I finally removed my pci-e graphics card and dusted it clean. I noticed plenty of dust in between the the card's heatsink and chip so I removed the heatsink and very carefully cotton swabbed the surface of the heatsink and around the chip. I then took q-tips to the motherboard cleaning up excess dust. After putting everything back together properly and exactly the same way I took them apart, I tried booting. Normally my computer (presumably the mobo) makes a few beeps just as it is powered on (to which I have come to understand as post) but instead there was none. I also noticed none of the video outputs were working. I have two monitors plugged into the one video card and none of them were receiving any sort of signal from the card (ie instead of the monitor's power light going green they both simply stayed at the flashing orange indicating standby). After freaking out for a bit I tried reseting the cmos. there were three cmos pins; my machine only powers on when the jumper is in "normal" mode and will not respond to the power button at all when in "clear" mode. I also tried removing the lithium battery on the mobo for 10 minutes and reinserting it but to no avail. My system just keeps doing the same thing; powering on puts all of the systems, cpu's, and graphic card's fans in motion, and powers the hard drives. The mouse and keyboard lights came on and stayed on the first few times I tried booting but now and after disconnecting and reconnecting them they only light up for a second at the very start of a boot and then turn off. I have tried almost everything else I can possibly think of and read in forums online and I have yet to find a cure for this problem. I have also tried removing the video card and pluging a monitor into the onboard video output before and after an attempt at cleaing the cmos, still nothing. What bothers me is how it seemed to be working fine before I began dusting. Below I have listed my system specs: LGA 775 mobo with 2.3gz Dual Core P4 2 dual channel sticks of 512 ddr2 ram pci-e 16x 256mb geforce graphics card 500w power supply One thing that was fishy is that every once in a while (about once a month) my pc would shut itself down during intensive graphical or processor heavy use. A simple flick of the power supply from on to off and then back on again would fix this problem immediately though. If you have any suggestions please let me know as I am running out of ideas and it is urgent that I get back onto my computer and finish the work that I was in the middle of. Thanks in advance for any support.