Idk, either way, it's pretty annoying.
For reformatting: You lose all your stuff unless you back it up which takes quite a while. But, you do become completely clean.
For searching for a fix: It takes a while, I guess. But you fix your errors.
Also, I at least needed to repair my comp with the CD. Stupid AVG finds a Win32/Virut error everywhere and automatically removed all the necessary stuff.