Folder Locker Professional "Incorrect password"

Registration date
Monday October 17, 2016
Last seen
October 17, 2016

I have been using Folder Locker Professional MRT for the last three years. It has never given any problem. However, last week when i tried to open the locked folder it said "Incorrect password". I can not access it now. It is installed in D drive and the uninstall option is also in the locked folder. The 'uninstall programs' list in control panel doesn't show it either.

I read some of the threads here about entering the registration key and deleting it by running 'regedit'. I also tried by installing it in the same drive and the uninstall it again. None of them worked. Please help me out. How do i open/uninstall it ?

PS: I use Windows 8 in Dell 3420. The software was in the disc i installed windows from.
Thanks in anticipation