The XP Pro upgrade, from Windows 2000 Pro, should not require to re-format
the drives. However, if you are planned to do this type of upgrade because
you wish to fix a Windows 2000 Pro Windows problem, then do not do this.
The problem may not get fixed and can cause most problems.
The preferred way of upgrading to Windows XP is to do a clean install of XP.
The XP retail upgrade CD will allow you to do a clean (fresh format) install
of XP. All that is required is your complete Windows 2000 Pro installation
CD (not a recovery CD) so that XP can find the required files to justify the
use of the upgrade. Of course, since you have formatted your drive(s), you
will need to re-install all your apps, since they were erased by the format.
Y.