can I upgrade XP home to XP pro without losing any info
First try Repair XP
OPTION 1 - Repair XP by replacing corrupt files Type
in the run box, press enter and let system file checker find and replace missing / corrupt file in windows and explorer.This will take awhile to complete and you may be asked for the CD to be in the drive if windows is not preinstalled on the hard drive.
sfc /scannow problems http://www.updatexp.com/scannow-sfc.html
Do not attempt to reinstall XP without first being sure evrything is backed up you have the product key and the backed up activation files WPA and all drivers and install files / disks for any programs on the system.