Take certain actions based on the number of NSIS instances running

Hi, I am trying to take certain actions based on the number of NSIS instances running.
The main reason is that if there are two instances of the same executable the data created is overwritten

I asked in the NSIS forum but the code provided doesn't work. I wanted to put the code in multiple sections, the one provided by the NSIS forun can only be used once.

If there is only one instance does it perform an action, if there are two or more does it perform another

You can check if multiple instances of a process are running and take actions through "if" and "else"?