Problem with GF8800 GT on vista home edition crashes on boot

Ok Ive had Vista Home Premium for about 8 months now. Ever since I installed it on my desktop it has this strange boot up problem. Basically I press the on button it goes through the usual boot process after the little loading sequence with the windows logo just as its about to load the small circular vista logo where I can enter my login password. The screen turns into a multi-coloured mess, however I can still hear the vista welcome sound so the system technically hasnt crashed. Its as if it just cant render the GFX of vista, its just a mass of multi-coloured squares. So I press my reset button and boot up again, guess what it works fine. I have been booting up twice for the past 8 months to get into vista and its starting to annoy me now. Any ideas? my spec is bellow.

Spec

CPU: Intel Quad Q6600 2.4GHz

GFX: ASUS GF8800 GT 512MB (Forceware version: 169.25)

Mainboard: Gigabyte P35-DS3

RAM: Giel Blackdragon 800Mhz 4x1024MB

Sound card: ASUS Xonar DX

HDD: 3 x Samsung Spinpoint 500GB

O/S: Windows Vista Home Premium Edition 6.00.600.1 (Service Pack 1)

Updated the nvidia drivers to version (178.24). No longer do I get the multi-coloured blocks when i boot up. Just a blue screen which shows some information then disapears before I can read it. I then re-boot up again, get into vista fine. And a Windows solution box pops up with this information: