I tried using Mozy in the past, but had nothing but problems with the Windows client. It would constantly just stop working--with no rhyme or reason. The only fix was to wipe my data, uninstall and re-install. After a few times of that and trying several upgrades of the Mozy client I gave up. Not only did it take forever to re-upload my data, the fact that was so unreliable was enough for my to give up on Mozy.

At the moment, I'm just backing up to a local NAS and also syncing important data between my PCs and laptops.