XP boot hangs after software install

Athlon64, XP Pro, 1G RAM, parallel printer, USB scanner, USB kb, USB mouse

XP hangs almost every time after new software is installed or uninstalled.
It seems like it does it especially when the software wants to re-start to
finish the install.

The blue bar just keeps going and going and going. Sometimes it freezes,
but generally it will keep going for 15 minutes ormore and never boot. I
never see any HD activity during this time.

I press the reset button to restart and sometimes it boots when I chose
"Start Windows Normally". Other times I have to "Use last known good
configuration".

Any ideas? I'm so glad I found this group!

Bruce