ok... windows 8 does it differently.
trick is 99% of the safemode boot options for windows 8 don't work if you can't load into windows first (hows that for retarded?)
there is an outside chance you can get into safemode by mashing "shift+f8" during windows startup (before any windows splash screens), however if you have an SSD it's unlikely you'll be able to time it right to work.
If you can't get it into safe mode using shift+f8, then you'll have to use your windows disk, to load into the recovery console, and try to fix your windows install from there.