Blue Screen after startup

[Jerry]

Upgraded from XP Home to XP Pro. When the computer
restarted the screen goes blank. How can I fix problem
or uninstall XP Pro and revert back to XP Home

 

[Rich Barry]

Jerry, usually that is one of the simplest of upgrades. You may have to
format and start over. But first try a Repair Install.
http://www.michaelstevenstech.com/XPrepairinstall.htm