Depending on how you installed MSDE, it may need a Server name (instead of local).
Try the following
1. Use the actual ServerName instead of (local)
2. Try ServerName\VSDOTNET (sometimes MSDE installs and gives itself the VSDOTNET Instance Name)
Also I am assuming that MyUser/MyPassword is an MSDE User not a Windows User.
Charles Nurse
Keydance Computer Services
Langley, BC, Canada