What is srstop, and how do I use it?

[BonsaiForest]

A copy of Chronicles of Narnia has a file that says "use srstop". Normally, the game refuses to run because it can't find it in my physical DVD drive, when it's in my virtual one.

I assume "srstop" is some feature to prevent it from doing this? I searched that term and couldn't find anything useful. Any help?

[NetSoerfer]

I never heard of a game that came with anti-copy-protection tools...