XP Won’t Shutdown right after reinstall

I have ran into the problem of Windows Xp Pro not shutting down after a reinstall (not a clean install, just reinstall).After leaving the desktop area to enter the shut-down mode, the shut-down dialogue says or I should say my option are “Turn Off” , “Restart” , but no more
“Standby” option is available. On top of all that when I go to “Turn Off” and Win shuts down
it tells me that…”It is now safe for you to shut down your computer”. Be fore it would just shut down. Also, I had my pc able to turn on with a one touch key stroke and it no longer
works correctly. I run a legal copy of XP and have thought of formatting my HD to fix the problem, but if anyone knows a Reg hack in which
I can reset this shut down feature, I would have to say cool. My bios has not changed.