Most PCs today ship with two partitions on the hard drive. The main one, C:, contains Windows and all of the junk you don’t want that the vendor installs. Eventually, that partition will also contain everything you want on your computer.

The recover partition, usually D: if it’s not hidden, contains an image of C: as it was when the PC left the factory. If your Windows installation becomes corrupt beyond hope, or if an incompetent tech support person simply wants to get you off the phone, you may end up using this partition to restore Windows to its original state.

And when you restore your hard drive using that partition, it will revert to the OS it came with, probably XP or Vista. That partition cannot be updated.

On the other hand, you can create your own Windows 7 recovery backup onto an external hard drive, and I strongly recommend you do. Windows’ own Backup and Restore program can do this, as can Macrium Reflect Free and any number of other image backup programs.

Even if you weren’t upgrading Windows, this makes a better recovery tool than the recover partition because it will restore Windows as you set it up, not as it left the factory.

If you want to be extra cautious, you can keep the recovery partition as well–just in case your backup fails. Of course, if you ever have to use it, you’ll then have to upgrade to Windows 7 all over again.