I have a user that has a 9630. He was using the USB to charge his phone and transfer some photos from his phone. When he hooked it up and went to the E:/ drive that was listed in his directory, it linked him to a network drive on my server. I tried it with my phone and it would not connect.

He does not have mass storage turned on, but it does prompt him when he connects.

The directory on the server that he connected to is not one that is accessible to most users by default. I just don't know how it is mapping itself to the directory.

Are you sure the "E" drive on his PC is linked to your server. Any drive letter can be mapped to any other server or shared location.

It is not a mapped drive. I thought that originally and went to map the drive and E: was available. Also we map H: to the users local folder on that drive so that would be his only access to that drive on the server.

I would check to see if the folder/drive is broadcasting or allowing anyone to connect to it. It seems there is a setting somewhere allowing this. I would start with the users PC and check options. Also see if you can watch what happens when he connects the BB.

some thoughts
The user does have access to the drive via his account
The "E" drive is the next available drive on his PC and the BB found it available.
why is the "E" drive available on his PC.

The drive letter is irrelevant. Instead of seeing the device the computer is linking to my server. Is there a setting on the device that would do this? I have several users, including this one, that have been doing this without incident and this is the first time I have seen this.

No there's no setting on the BlackBerry device or the BlackBerry Desktop Software to determine which drive letter the device or media card is assigned.

Whatever is happening here (or for he/she) is related to the PC Desktop and not the BlackBerry... in other words, you're looking in the wrong direction.