.ERF files for mods

I just recently got a computer virus that killed almost my entire harddrive.  It's been fixed but lots of files were corrupted.  Now when I download a mod that has an ".erf" in it, the file associates with the wrong program; it was associated with Microsoft's Photo Gallery for the longest time.  I found out online that they're probably supposed to be ".gff" files which is:  The Generic File Format (GFF) is an all-purpose generic format used to store data in BioWare games.

Does anyone know how I can get these back to being the correct files so I can use the wonderful mods I had before my computer tried to get killed?  They're for both Dragon Age and Dragon Age 2.

Anastasia