Protected operating system files that are safe to delete.

Well for some reason my computer keeps relagating onenote files (that I accedently created) to being system protected files, no clue why. Well that and there are other files that don't seem like they should be protected files. My question is is there a list or does anyone know of files that can be deleted safely? I also ask this so that when a virus desides to masquerade as a system operation file I can kill it, well change the extension to a crazy series of letters and numbers to make it non-operational like .ñajdlfjkañldfoanflkansñlfhaoñsfjaoiefreljfoe for instance. Anyways I do have to know, can I safely get rid of desktop.ini files? Thanx in advance.

I forgot to add that when you have microsoft word messup and restart for some reasons it sometimes saves the temporary quick save files as protected files too. So again, any lists or files that are ok to get rid of would be much appreciated.