Backup utility that does not create proprietary file format?

[TwIce]

I'm looking for a data back up app or utility that is non-invasive and not bossy or a hog; my last one would save files in a proprietary format which can only be accessed via the program that created it, so I reverted to simply copying and pasting folders in Windows.

My experience of these programs is limited. Ideally, all I need is something that I can install on two PCs, can remind me to back up chosen data files and remember where they go on one backup drive with separate backup destination folders for each PC. I'm hoping to use this app to select source files (My Documents, iTunes, etc.) one time, set the destination location and folders and then automate the process.

I'm running Vista 64x. I do not mind paying for a small-footprint app that does not install crapware.

As always, Sharksters, thanks.