Restoring Database using SQL-DMO gives me an error on another DB Server

Hi I am trying to restore a database using SQL-DMO. Restoring works on my development computer, but it does not work on my colleague's development computer. Although there are no users using the database in question, I get the following error message while attempting to restore the backup file:

Exclusive access could not be obtained. Database is in use.

Do I have to do anything in particular? Here is my snippet of code (VB.net). Thanks.

Dim my_srv As SQLDMO._SQLServer = New SQLDMO.SQLServerClass
my_srv.Connect(my_config.get_ServerName(), my_config.get_DBUserID(), my_config.get_Password)

'COPY FILE TO SPECIFIC DIRECTORY ON SERVER
Dim my_file As File
my_file.Copy(Me.txtFilePath.Text, "\\" + my_config.get_ServerName + my_config.get_backupfolder_string + "tempcas.bak")

Dim my_restore As SQLDMO.Restore = New SQLDMO.RestoreClass
'my_restore.Devices = my_restore.Files
my_restore.Action = SQLDMO_RESTORE_TYPE.SQLDMORestore_Database
my_restore.Files = "[" & my_config.get_backupdrive_string & my_config.get_backupfolder_string & "tempcas.bak]"
my_restore.Database = my_config.get_Database()
my_restore.ReplaceDatabase = True
my_restore.SQLRestore(my_srv)
MsgBox("Database restored successfully.", MsgBoxStyle.Information)

'DELETE TEMP FILE FROM SPECIFIC DIRECTORY ON SERVER
my_file.Delete("\\" + my_config.get_ServerName + my_config.get_backupfolder_string + "tempcas.bak")Make sure you are not using the same database which using the DMO script.
Try using MASTER database instead.|||Hi, sorry, I'm not following you. Could you elaborate more?

Thanks!|||When you connect, what is the database you are connecting to ?|||I'm connecting to a database named CAS. Anyway the database name would vary on what I have set in an xml file. As you can see from my code, I am getting the database name from a class.

I've found that it is because my query analyser is open and pointed to CAS, this causes a process to be created. I can see this process with a status RUNNABLE, dbName CAS and program name SQL Query Analyser when I run sp_who2. When I change query analyzer to point to another database, this process will disappear and I would be able to restore my CAS database.

Is this what you were trying to tell me? Thanks for your replies.

I am now concerned about what would happen if there are multiple users using the application.