Registry locked disaster

Running Windows 8.1. Had a brief power outage, 10 seconds. After power was back on have had all kinds of problems. For example FireFox keeps saying I need to make it the default browser after I do so at the popup and in the options. A couple of free software applications say I must activate the professional version which I never ordered. One application says I need administrator rights to unlock the registry. I am the only user on the machine and have full admin rights.
That gives me a clue something happened to the registry with the outage. When I Google how to unlock the registry I get a LOOOOONG disertation on how to use another computer to download software, create a CD, then go back to my computer to my computer to fix things. Another annoying thing is the keyboard rarely does not process a specific function unless I punch it about three times.
Any suggestions or advice are greatly appreciated.
Thank you
Mike

 

First thing to try is system restore. If that is not successful then you could refresh 8.1. Here's Microsoft on how -

http://windows.microsoft.com/en-us/windows-8/restore-refresh-reset-pc