ohk this can take a while but well get it done.not your fault.for starters install your standard graphics drivers the ones you got with your computer

I installed it already and still the same thing happens. I also tried installing the latest version of the driver but the computer still freezes and shows white screen.

The computer freezes after reboot, just after displaying welcome. This happened twice already.

ditso I need for you to open your box and see if you have an integrated graphics card or an graphics card thats in a slot.will you be able to do that??

yup sure. just tell me where to look. thanks!

before you open or unplug anything look @ the back of your computer box and see where your monitor cable plugs in(the one with the pins-thats your signal cable)now that you've seen where it plugs in open your box and see from the inside if the connector (where the cable is connected to )if its actually soldered to your motherboard or is it on a seperate card

it's soldered to the motherboard.

integrated =onboard

...so ill suggest you get a 'cheapie' of a graphics card install it and see how it behaves
dont buy one just find one for troubleshooting

good suggestion I also suggest a ram test program ,download iso and using a iso burning program burn iso to disk and boot computer to this program memtest 86.of course you will need to do this on andother computer because of your problems.
memtest86=http://memtest.org/#downiso
Image burn =http://www.imgburn.com/

ah ok. here is what is wrtten in the manual of my motherboard:

OnBoard VGA: Intergrated UniChrome PRO 3D/2D Graphics Controller
, supports DirectX 8.1

by the way, what should I copy here after the ram test?

ok i'll look or borrow graphics card.

thanks!