What are these strange environment variables?

Question

I use GetEnvironmentString() to get the program\'s environment variables.

Every program has such result in the first:

=::=::\\


        

Answer 1

They are leftovers from cmd.exe emulating ms-dos directory handling, they basically have little use, and are more archaic than anything. Essentially, it keeps track of a per drive current directory, and is kept as an environment variable to pass to other processes with ease.