Upgrading Windows 2003 Evaluation Edition to Enterprise Edition

have a large number of virtual pc's, some of which were installed with the evaluation edition of Windows 2003. I tried to upgrade some of them recently to Windows 2003 Enterprise with SP2. Basically there is no upgrade option, one does a repair using the Windows 2003 disks. However I kept getting the message that the repair could not find install.exe on disk 2. This file does not exist on disk 2. The workaround is to uninstall the .Net framework 2.0 and upgrade and then reinstall the framework afterward.

Update: I have also succeeded without uninstalling the .Net framework 2.0. I have unpacked the .Net framework and pointed the Windows 2003 to this install.exe file when it asks. Installation works fine, but I likely because I have 2.0 SP2 I have found that I also have to repair the framework after installation.