Ok... I'm a little stumped on this one...

This is what I'm currently working with:
Intel Celeron D 331 Prescott 2.66GHz LGA 775 Processor Model
ASUS P5PE-VM LGA 775 Intel 865G Micro ATX Intel Motherboard
Kingston ValueRAM 512MB 184-Pin DDR SDRAM DDR 400 (PC 3200) Desktop Memory Model KVR400X64C3A/512
SAPPHIRE 100562L-GN Radeon 9600PRO 256MB DDR AGP 4X/8X Video Card
and a 420watt micro atx case.

When I first put it all together, the video didn't work, so assuming the card was bad I removed it and plugged directly into the onboard video. All was well until the next day while updating windows the screen basically turned to gibberish pixel wise. I proceeded to restart the computer and now I'm receiving the same error message I received when I was trying to plug through the Sapphire card. My monitor comes up saying "no signal". When I power the computer on I can hear the CRT monitor warm up and then come up with no signal so it can tell when I'm powering it on and off. Assuming it was the PSU I removed it and took it down to be tested. "Came up green across the board" in their words. I've heard that bad memory can cause this to happen so I removed the ram stick from it (I BELIEVE this works... if not please correct me) and still received the same error. Help please cause I've become clueless. Thanks

Ok so first, you removed ram from the PC right? Cause it seems like your implying you removed it from the moniter.
1. Your first step is to make sure the moniter works (you know the power supply works, but does the connection work?). Test it on a laptop, a friends house, at work, anywhere.
2. If it works continue, otherwise, skip to step: 8
3. Now that we know the moniter works, try it again on the onboard video.
4. If no go, then continue other wise you have it working, cry with happiness.
5. Install you video card, and plug the moniter into it, the computer should treat this as a plug and play and should pick it up right away, if it does not, continue on;
6.Try it again, after unplugging your hard drive, Still not working? Plug back in your hard drive and continue on.
7. If you have a nice friend, or a spare tower, attempt to install the video card on their PC, if the card works for them, test it with your moniter, if both work, it's your motherboard. Continue on
8. Go to the store and replace it.

Questions? Comments? Good jokes?