The best place to find what is wrong with windows is the event log. In order to start the event log type “Windows-R” and:
eventvwr
Or you can simply open a command prompt and again type:
eventvwr
In powershell the command will be:
evenvwr.msc
In control pannel you can search for event.
You do not find anything? Just take a look at your users on the computer. Is it possible someone hacked you and you have an extra user? Open a command prompt as admin and type :
net user
Make sure there are only the users that should be and not others.