hell, that is the hard way.
go start-control panel
go to classic view
go system, advanced tab.
click the startup and recovery-settings button.
click the edit button.
one of the bottom two lines will say vista, somewhere. delete the line you want to get rid of. ONLY DELETE THIS LINE!!!! or your whole system will crash. but it is safe to delete this line.
save and exit.
Voila!
Never begin a job by looking at a computer and saying, or even thinking "this won't take long..."
If all else fails, use a bigger hammer.