You need to provide a user name and a password if you want to connect to a Windows server through VPN using PPTP. Has the provided user name any function?
Let's say you use the user name "John" to connect to the network using PPTP VPN. John doesn't have the rights to acces the folder "B" on the network. Does that mean I too can't access the folder if I use John's user name to connect (in the Windows own VPN connection dialog)?
Or is the user name completely meaningless and just establishes a tunnel over VPN and has nothing to do with the ACLs in any way?