Sorry to spoil the party,but there are reports of Vista refusing to boot up after Linux is installed,though those cases were on boxes with single HDDs.If your friend has 2 HDD's,then no problem,he can install vista on one and linux on the other but it involves some drive swapping as illustrated in the link below: http://wiki.gtwy.net/index.php/Dual_Boot_Vista_and_Linux Also,another link is; http://www.pro-networks.org/forum/about78184.html
Regards, Easwar