Tom called about installing Windows into a new directory…
For testing, as well as performing a clean installation, my preferred procedure is to:
boot to a diskette or CD…
create a folder called “boot”…
copy all files on the root of the hard drive to it…
rename the “progam file” folder/directory to “oldprog”…
rename the “windows” folder/directory to “oldwin”…
and delete all files on the root of the drive.
The Microsoft website has instructions on how to “Perform a clean install of Windows XP“.