Hi, i'm have problem booting my computer up.
Upon booting Windows XP logo I would see a blue refresh bar moving down the screen. Then it just show the Blue error screen and restart itself.

At first I think my graphics card is fryed but when I take the graphic card out from the motherboard and put it back(without securing it and left the cover plate opens.) It would boot into Windows just fine even w/o the blue refresh bar. No matter how many times i restart the computer it would boot fine.

Now when I secured the graphic card with 3 screws and put the cover back. It would start doing the blue refresh bar and won't boot again!!

Then I take the graphics card out and put it back w/o screwing it back. It would boot up fine again!

My graphic card is the geforce go 5600

Please advise what's wrong with the computer?
What needs to be replace?

Thank you!