UAC = User Access Control
It is what pops up every time you want to run something as administrator. Suppose to help keep viruses out, doesnt come close lol
And yes stick With 7 for now.
MS has a long history of every other IS being good and the other bad.
Windows 3.1 = Bad (Only because it was the first of its kind)
Windows 95 = Good (Good as it was the starting point of home PCs growing like nothing else)
Windows 98 - Bad (Lots of new things since 95 but unstable and a lot of bugs and missing things)
Windows 98 SE = Good (Bugs worked out and became the most use OS before XP, and was levels better than 95)
Windows ME = Bad (Why the hell they put this out I don't know, but was one of the most unstable and unliked OS's besides vista)
Windows XP = Good (By SP3 XP was rocking and was on almost 95% of pcs)
Windows vista = Bad (Event though they fixed a lot of bugs and made it more stable the damage was done and still not as good as 7)
Windows 7 = Good (What vista should have been, but they pushed vista out to quick, kinks worked out, lower memory usage and faster core.)
Windows 8 = Bad (New UI changes back fired, they are trying to get a piece of the app store pie, seems to be their test bed for so many new things. The worse thing you can do is change the interface that generations have learned on, like taking a bullet in the foot on purpose. Change is good yes, but make change an option, no so drastic)
Windows 9 = Unknown (Will be out in a few years. MS has a way of learning from the last OS since they like to use every other one as a test bed for new things, then keep what worked and dump what didn't)