If you have any Winamp version older than 5.05 installed, you have a major
security gap in your computer (even if you don't run it!).
It is critical that you patch it either way:
a) Upgrade Winamp to 5.05
b) Double Click "My Computer"/Tools/Folder Options/File Types, find extension "WSZ", click advanced and mark "confirm open after download"
OR
delete WSZ extension altogether.