Can't Attach To DB File Using SSMS

Hi all,

I have "SQL Server Express" as well as SSMS-E installed on the same machine. I am trying to get SSMS-E to connect to a database (i.e., an .MDF file) that resides in a folder on the desktop.

After establishing a connection to my "SQL Server Express" instance within SSMS-E, I right-click on "Databases", in the "Object Explorer" window and select "Attach..." and click the "Add..." button. The resulting dialog box opens in the directory:
"C:Program FilesMicrosoft SQL ServerMSSQL.1MSSQLData" where I see several MDF files. But as I said, my MDF is not in this directory - it's on the desktop.

If I try to navigate to the proper directory on the desktop I see no MDF files. In fact, I cannot even navigate past my username -- that is, I cannot even navigate to the desktop, let alone folders on the desktop. I don't know why.

Of course I *could* put the MDF file in the SQL-E approved directory but shouldn't I just be able to navigate to it using SSMS-E? Incidentally, I *AM* able to connect to the database on my desktop if I use Visual Studio and I specify "UserInstance=true". Not specifying "UserInstance=true" results in this error:

An attempt to attach an auto-named database for file C:Documents and SettingsRobinDesktopMyCompany.mdf failed. A database with the same name exists, or specified file cannot be opened, or it is located on UNC share.

Can someone explain what might be causing the problem with SSMS-E, and, for that matter, why it's necessary to specify "UserInstance=true" in Visual Studio?

Thanks so much. I hope these are not too many questions.

Robin