Oh...well...you could have done that without a System Restore...
So, here's the good...
System Restore generally works, but can take a long time (several hours at least) depending on the machine it's being run on and how old the restore point is.
Since Windows 7, System Restore has been pretty stable, and normally will work. I haven't done a restore on 8 yet (though I have 16 of them, including my laptop and my Surface Pro), but they haven't changed all that much since 7 (in that respect...the UI has changed a LOT, and a bunch of other things which I will spare you from a list of).
The bad...
Once you've started the process, you can't stop it. If you do, the machine will most likely be a paperweight (unless you want to do a restore install off some original installation media or do a clean install).
So...it's sortof like Windows Updates...you just have to let it run it's course.