increase FSB from 100 to 133 & XP hangs on Opening

I installed XP with my Bios on 100 FSB, not knowing I
should have been running 133 to get the full speed out of
my AMD 1800+, it was showing up in the boot up as 1150+,
now when I try to change it, XP hangs and will not open,
if I go back to the bios and put in FSB 100 it boots fine.

Does XP make require a reinstall because it was set up
with FSB 100 initially or something else going on. I have
a current MSI KT4V board which works with up to 3000+ and
I have a current bios.

Does anyone have any reality on this issue?

Thanks in advance!

pooch@nctimes.net