[Windows Vista Installation Error]

Hii,

I currently have Windows XP Professional installed. I wanted to install Windows Vista Ultimate, when i inserted the DVD, Windows Setup screen was shown. When i click Install Now,i got the error

When i tried booting the DVD, after "Windows is loading setup file" is completed, it shows me an error

"Windows failed to start......"

winload.exe file is missing or corrupt.....

SO i cant install Vista in either of the ways. Can anyone help me out.

Thankyou

[Windows Vista Boot Image]

Thanx a lot Nepali