Microsoft has a step by step for that you can download direct from
Active Content Wizard
Another problem besides the need to backup and restore the registy is the need to see folders created in other locations under the user account as well as in the Program Files directory since the software installer creates those.
I figured you had already borrowed a monitor or were on someone's else's system in order to start thread here. The question now is why does Windows have to be reinstalled to start with? The installation files are usually on the softwares disks unless a program is saved in a folder when downloaded.