You could try something like the following.

USE MASTER

declare databases cursor for select name from sysdatabases where name not in ('master', 'tempdb', 'msdb', 'model', ...any other databases you do not want detached)

declare @db sysname

declase @sql varchar (5000)

open databases

fetch next from databases into @db

while @@fetch_status = 0

begin

-- not 100% sure of the detach db syntax 'coz I do not have access to SQL where I am - it might be incorrect

set @sql = 'sp_detach_db ' + @db

exec (@sql)

fetch next from databases into @db

end

close databases

deallocate databases