first off a simple dir /s *.mpg >c:\mpg.log

if you wanted to know what they are watching/playing you could ENUMVALUE HKEY_CURRENT_USER\Software\Microsoft\MediaPlayer\Player\RecentFileList
and or other players they may have installed

if you wanted to delete files older than a specified date / number of days, welll that is a bit more involved. You will need the datemath UDF fron the udf forum, and then do a dir on the specified directory, datemath it, the delete it if older than X number of days.

Is this sufficient, or do you want real code?