Problem: I installed windows 8 on a computer that previously had win xp. Now, when I boot up the computer I get a text screen with a bunch of OS options with my old windows (Win XP) as the default. I have to select Windows 8 manually to boot. I wanted to get rid of this/or make win 8 the default option Solution: (From here) I ran, from an administrative prompt (WINDOWS KEY + x + a)
c:\windowsto where ever your windows install is.