I just bought vista ultimate 64 bit. when I tried to install it(with 4 gigs ram) it had an error message. I went on my laptop and read some forums. Some people said that they could not install vista with more than 2 gigs of ram. I took out 2 gigs of ram and vista installed perfectly. I shut down my computer and put the ram back in. now when i turn my computer on i get a different error message. How do i get vista to work with 4 gigs?? thanks