Mine

Unable to open the physical file "C:\Program Files\Micrososft SQL
Server\MSSQL.1\MSSQL\Data\testing.mdf", Operating System error 32: "32(The
process cannot be access the file because it is being used by another
process.)".
An attempt to attach an auto-named database for file C:\Program
Files\Micrososft SQL Server\MSSQL.1\MSSQL\Data\testing.mdf failed.  A
database with the same name exists, or specified file cannot be opened, or
it is located on UNC share.