Hi Adam,

Could you please provide some more information regarding the issue?

1. Is this a clean install of Vista or upgrade over winXP?

2. Is it the latest build? (5728)

3. Have you been using any other OS successfully on the same machine?

4. Which motherboard are you using and what is the BIOS version?

If you can provide this information it would be easier to come to any sort of conclusions and provide you with the most appropriate suggestions.

Regards,
Vikas