I was a "love it" but I'm getting a tad irritated with some quirks.
Control of permissions is a clear one. Or to put it another way, when is an administrator not an administrator.
So, I have trouble with some installation, say, because the permissions on some folder or other won't let it access them, even though the permissions seem all to be set right. But when I come to reset those permissions it won't let me ( administrator account) change them, because admin isn't good enough.
Another is uninstalling or reinstalling. Frequently the source file for a .msi install is missing, because it had saved itself in a temp folder. But Windows won't/can't uninstall the programme without it. And, more to the point, it won't let me reinstall over the exisitng installation, so that I can then have the files to uninstall it with, because it needs to be removed first, which is what I can't do. Catch 22 anyone? (Revo......!)