Take a step back...
Did you install a new motherboard and then try to upgrade
your win98 to xp WITHOUT fixing win98 first?
You need to get win98 working again before win xp with
install.
The easiest solution is to do a format install with win
xp, if it is an upgrade only cd just have your win98 cd
handy, there will come a time when the xp install will ask
you to validate your upgrade copy by putting a cd in of an
older version of windows (i.e. win98 cd)
Take note, that if your BIOS settings are wrong, your xp
install will HALT. A known wrong setting in Bios that
will cause this is an incorrect FSB setting. The XP
install appears to look at ID tags to that it knows what
your processor is. But for example, if you put in an
ATHLON XP 1700, and set the FSB incorrectly, BIOS will
detect it as a 1100. Windows install will see a conflict
and FREEZE!
Hope that helps
Dean