Open an elevated command prompt (right click and run as administrator) and enter the following (assuming the directory you have a problem with is "F:\Problem Directory" - otherwise you'll want to change the bit in red...)
This will take ownership of the directory and then grant authority to the current user.
takeown /f "F:\Problem Directory" /r
icacls "F:\Problem Directory" /grant "%USERDOMAIN%\%USERNAME%":(F) /t
Note: no need to change "%USERDOMAIN%\%USERNAME%" with your user name - just enter it as it is above.
While you could give yourself authority to everything like this it would be a bad idea as any malware you got would also get full authority and also some programs might expect default permissions and act erratically. I'd not mess with permissions in directories other than those just containing your data (i.e. not "C:\Windows", "C:\Program Files" etc).