In order to make changes to boot.ini or indeed clean any virus from an ntfs filesystem you have to use captive_ntfs (or if you're using a live cd you have to activate the ntfs read/write using captive_ntfs). And if your friends computer is updated to sp2 then you'll have to use a workaround which is located here.
http://www.oreillynet.com/pub/wlg/6261
The file that captive_ntfs needs is called ntoskrnl.exe
this file is usually found on the hard drive, if it's not there then it can be found on the winxp sp1 or maybe sp2 disk or it can be downloaded here
http://members.driverguide.com/drive...driverid=30670
Knoppix will probably be easiest to work with but there are other livecd's specific to security here's a list.
INSERT
PHLAK
UBCD
...and more.
So give it a try.