SQL Server 2005 Express: In Database Properties Transaction log filegroup currently says 'Not Applicable'

The database files (mdf ldf) were taken from a crashed machine and loaded using the attach method. Since everything has been working fine, except when i try to truncate the transaction log the file size does not change and i now notice that it says Not Applicable against the filegroup entry for the transaction log in database properties.

Is the transaction log not active? Did i not开发者_如何学编程 attach it correctly? How can i check?

EDIT: There is no option to backup the transaction log in the Backup Window of management studio express either

This is standard behaviour - log files are not part of any filegroup - I've just checked a couple of my databases to confirm this (I wasn't sure one way or another but I am now) - so nothing to fear.

Regarding not being able to truncate the log file, which recovery model are you using?