unable to restore a .bak file in SQL 2012

Environment: SQL 2012 SP1 Standard on Windows Server 2012 R2 Standard (Hyper-V instance on 2012 Standard)

I've been trying to restore a backup file that was updated on another system by our vendor (Omnify)

I'm getting the error: Omnify5.mdf cannot be overwritten. It is being used by the database Omnify5

I've tried putting the database in single user mode, Ive tried taking the database offline

I've tried rebooting

I've tried the following code:

useMaster;

GO

alterdatabaseomnify5

setsingle_user

withrollbackimmediate;

alterdatabaseomnify5

setmulti_user;

Go

And I've checked file permissions

I've verified the BAK file

I've re-created a backup to see if I could restore using it and still no joy.

Anyone have another idea?

Thanks

Jim Bogart "bogart dot james at gmail dot com"