Checking the File Format
 

How do I check the file format of my song? Right click and properties only gives me "winamp media file".

All you need is to know the extention (or advanced users could use a hex edittor). If the file extention isn't listed, provided you're using Windows Explorer to view the properties rather than Winamp, go to Tools > folder options in Windows Explorer. On the view tab, scroll down a little where you see "hide extentions for known file types" and remove the check. Now Windows Explorer shows the file extention. For setting the file types in a more worthy way, this process is a little more complicated.

When renaming a file, however, you need to manually include the file extention into the file name.