I am having the same issues, if you are running windows may I ask if you had a critical update you just installed. I had one and that is when my troubles began.... I have tried to restore and it worked once and when I left for the weekend and came back the update installed again and now I am back to square one. the restore did not work this time. The reason I am telling you this is it may be the critical Microsoft update that started your issue, try restoring and then installing again....
I could point you to the offline installers, but since they will soon be unavailable publicly, I will let the Flash Player team handle this.
We have received numerous reports of this behaviour, but have been unable to reproduce. You can bypass the online installers by using the offline installer posted at the bottom of the Installation problems | Flash Player | Windows page.
You indicate the problem began for you after installing a critical update. Do you recall which update this was?
Thank you in advance.