step by step process.

The locking process:
Go to run, type notepad and then press enter.
Notepad opens now type
ren abc abc.{21EC2020-3AEA-1069-A2DD-08002B30309D}
abc should be the name of your folder. now save the notepad file with name as loc and the extension as .bat not as .txt
now run loc.bat and you can see that your folder does not opens.

Now the unlocking process:
Go to run, type notepad and then press enter.
Notepad opens now type
ren abc.{21EC2020-3AEA-1069-A2DD-08002B30309D} abc
abc should be the name of your folder. now save the notepad file with name as key and the extension as .bat not as .txt
now run key.bat and you can see that your folder opens.


Giving you the sample files edit them according to your need.