Vista - Unable to open WMP11

Ok... so my computer was unplugged for about a week. got it back the other
day. and when i start it up, McAfee (which has been installed and running
fine before) starts it updates and all that jazz. Windows media player is
running fine as well.

When i restart my computer i realize that McAfee had Uninstalled itself.. on
top of this no matter what i do, my media player WONT open no matter what. i
tryed opening the program itself, no, mp3 files, no, avi files, no. Nothing
can get it to open

So i did a system restore, restored it back to before i unplugged the
computer.

When it started up, everything was running fine again, except no matter what
i couldent open McAfee, it ran updates, and even got some firewall pop ups.

After the updates and the re-boot... everything went back to not working.....

to add to everything my side bar wont work either....