If you're doing the same computer, I think it may be acceptable to export your installation, and registry, and not have it count as an "activation" just because you reformatted your PC. That's what I do at least. Maybe that's wrong? Seems it'd be OK considering how many services that do backups of installed programs etc, and never heard anything about this being a violation of terms with other programs on the same PC. Sometimes installations use hardware IDs to determine an activation too so they know it's the same PC.