This piece of code does not do absolutely anything in the common understanding of the word do. This code contains only non-modifying query-type operations with no side effects, i.e. it makes some queries and verifies some conditions, but it doesn't make any actions based on the results of these conditions.
In other words, if this code was fed into some hypothetical super-optimizing compiler, which also knows the Windows API, that compiler would simply throw out (optimize away) the entire code, since it doesn't do anything.
Apparently, the code you provided is fake - it is not the whole code. Without the whole thing, it is impossible to say what it was supposed to do. However, if we guess that some useful functionality was supposed to be present between the {}
in the following if
if( GetDriveType( Drive ) == DRIVE_REMOVABLE )
{
// Actually DO something here
}
then we can make an educated guess about what it was supposed to do. This code iterates though all possible single-letter drive designations in a Windows system. It checks whether a logical drive designated by that letter is present in the system. And if the drive is present, it checks whether this drive works with removable media. And, finally, if it is true, then it does something useful that you are not showing us. I don't know what it was. Nobody does.