What version of BearShare are you using? The most recent version has no way
to filter out those DRM crap files.

If you have a version older than 6 there are two ways you can filter out the
bad files.

The permanent way is to go to the Setup menu, choose Filters and add several
file extensions to the list on the right. The ones you want to filter out are
WMA, WMP, WMV, ASF, and ASX.

The temporary way is available on each search. At the bottom of the list of
searches you have made are three filters. Select MP3 in the Type filter and
that's all you will see in the results.