I know this is probably an easy pone but I am bashing my head trying to figure it out.

This is not for school assignment it is for me trying to create a dynamic small application.

I need to run an application from a pen drive. Since different computers call the drive by different letters I need to discover the drive letter and then check for a folder existence. If not there I will make the folder(I know how to manke the file) and ftp from network to the folder then run the items. If it is there I just run the items

My difficulty(probably due to brain freeze) is how to get the drive letter. Everything else I cam already do.
thank you