Monitor Display Problem

Yo guys, i'm going to try to explain my situation here. My computer was working absolutely fine. Nothing wrong. I'm on XP SP3 and stuff is just dandy. I decided to upgrade to Windows 7. I did a full clean install booting from disc, setup completed and said it had to restart. All hell breaks loose here. First, the monitor would turn on so the bios start screen would pop up, then when it SHOULD show the next windows 7 loading and all that, it just says no input. I did a bunch of research and found that its a problem with win7 and DVI connections, and vga is the only thing that will make it work, which my card does not have. I tried a really old card with a vga, and i got in perfectly fine, and no matter what i did i could not get the dvi working on my good card. So, I say, hey to hell with it. I get my xp cd out, i pop it in, setup starts..it formats the drive.. then it copies the files, then says system restart..ok. It restarts, and now my monitor won't even show BIOS SCREEN?? I unplug my HDD from the mother board, so it should only load bios now..and BLAM still doesn't work. I switch cards, and it works to the point where i get to see windows install all the rest of its stuff, devices and all that, then restarts, and BLAM now its doing it to this card. I have a really bad feeling windows 7 ate my computer for lunch. How is this even possible that win7, after being FORMATTED AWAY still is screwing with my vcards? NO SIGNAL on monitor ftl. The only way I can even get back to bios now is to flash cmos, and then i can get in, the second i hit save and exit, it starts doing it again. Please give me any advice. I've tried 3 cards, all just give no signal. I actually even got in to windows xp, after the install...on my nvidia card, i was like YAY its working , so i installed my network drivers and mobo drivers...it says restart to finish, i do so..blam..now its happening to this card, can't even see the BIOS SCREEN... its just ...no signal.... even though it was just working..perfectly..fine.

ABIT IP35 mobo
trying ATI 4890 card
a nvidia 8600gt
and ati X300

Theres absolutely nothing i can do now to get any card to show me my bios or even load up, and i'm quite sure its loading to windows and i just can't see it.

Any help would be REALLY APPRECIATED... do i need a new mobo? can windows 7 problems really screw my mobo up so bad that i'd NEED a new one? i reformatted my hdd fully so thers nothing left on it from win 7..

ps. XP USERS DONT FREAKING UPGRADE TO WINDOWS 7!