[NEED] Timer with locking pc after countdown

As the title say i need someone to build a timer , when the countdown is 0 to show desktop and lock mouse and keyboard (one program) and in the same program when all these are ready to multiply all the minutes from countdown with 0.13334 including minutes tranformed from hours.

Example:

I set up the timer 3 hours or 180 minutes
I play cs:go all this time
When timer is 0 all the programs will be minimized and i will see only the desktop and mouse&keyboard will be locked.
After that i want to show a message who will say something like that:
you' have played 180 minutes
You have to pay (and here i need in program to multiply the minutes played with 0.13334 [180*0.13334])
And to be able to unlock the pc again i want a password


If anyone can do it please pm me or write here.

I can do this if its purposes are legal; your example looks like an internet cafe.

How would you re-enable it if the keyboard/mouse are locked? You need an admin computer to remote control this computer to add more time.

I will need more details. PM sent.

yes sound like some program for internet cafe, managing

I think Steam has a Cybecafe management programme.