>Hi to all..many thanks for your replies.
>
>I am not familiar with the concept of ATTACHING and DETACHING.
>it would seem from your replies that data is held elsewhwre, other than tje MDF amd LDF files.
>Anybody know where else the data is held (i.e.is it in another file, the registry or where ?
>Could I backup the MDF, LDF and A.N.Other file

The data are in the mdf and ldf, but not only there. The database properties are registered in master db (attaching), or removed from it (detaching) - which you can do manually from Enterprise manager or via a SQL script, of course if you have sufficient privilege. I assume the changes from transaction log are rolled into the db itself during the detachment process.

A regular backup, however, is a snapshot of the db in a format suitable for restoring. In this case I know the transaction log is truncated and all the logged transactions are rolled into the db (which is why I chose that moment to shrink it - saves a lot of space because the log is then empty).

IOW, the SQL server is set up in such a manner that the .ldf and .mdf are simply too connected to the rest, and copying them just like that is not sure to work, even if copies are just copied back a few days later. So you either disconnect them before copying, or tell the server to create a file that you can copy - the backup.