Windows 7 has almost hit RTM.  Across America hundreds of thousands are trying the release candidate (RC) build of the new OS. 

Unfortunately, that process may prove rather onerous.  Microsoft is using a "Custom Upgrade" process for those with Release Candidate builds installed.  This longer install is essentially a clean install with one key difference -- it does squirrel away your data in a folder called WINDOWS.OLD.

This is preferable to the alternative -- a re-install of your previous Windows disk and subsequent upgrade -- as you at least will be able to easy salvage your personal data, such as music or documents.

However, all the applications you've installed during your RC days will have to be reinstalled.  This will likely be even more of a headache when you're considering that you'll have to copy or import your various program user settings, saves (for games), etc.

Worse yet, if you want to reinstall Windows 7 for any reason down the road, you will have to reinstall the old OS if you upgrade using the "Custom Install".  So keep those XP and Vista discs handy, loyal Windows 7 testers -- you'll be needing them.

This issue won't affect non-testers, and is only a small inconvenience.  Given the value of Windows 7's new features and superior smaller footprint, it's a price most testers are willing to pay.  Still, it’s a bit disappointing that Microsoft wasn't able to come up with a solution to streamline the process more, for the testers that have helped it produce a hit.