Emb is the design format in Wilcom's software, which need to be converted to a machine format, like pes. What you can do is download Wilcom's (free) Truesizer to convert the emb-files.
All software programs have their own design format (like .can for Husqvarna and Pfaff; and .eof for Embird). It contains all information about the digitising process - the objects, the fillings, etc; and can not be used in other software than the one is was created in.
The machine formats contain the information your machine needs: the actual stitches and the stops to let you change colours.
Will this help you?
what kind of file is it? What does it say on the end?