If you have direct access to the SQL Server and can change the database options, you can change the database option "recovery model" to simple.  This will stop the use of the transaction log (mostly).  Once the option has been changed, immediately perform a backup, then shrink the database.  The log file should be reduced to a minimum size. 

This means that you can only restore your site with a backup file.  You will NOT be able to apply any transaction since the most recent backup.  So, depending on the level of activity on your site, this may NOT be appropriate.   Sites where very little changes or the lost of some changes can be tolerated, can consider this suggestion. 

If you will only ever restore to a backup, then this a suggestion to reduce the size of the database files.    However, I would recommend that you perform daily backups so in the worst case you will be only 24 hours from a backup.   Also, I would make a backup after any major change regardless of the recovery model used.

Paul.

Shrink the transaction file
back up all the data base and master before

ensure that you are in the right database DOTNETNUKE in QUERY ANALYZER
To reduce the size of the log file (. Ldf) to a SQL Server database must be from the Query Analyzer, execute the following commands:

BACKUP LOG DOTNETNUKE WITH TRUNCATE_ONLY
DBCC SHRINKFILE(DOTNETNUKE_LOG, 2)

The transaction log for the database DOTNETNUKE was reduced to 2MB.