I'm sorry to bother you catymag but i couldn't understand how to import GMAPSUPP.IMG to mapsource

I have mapsource installed on my pc

and I tried uploading the map to my unit and then importing it to my pc but it keep saying I don't have the map version installed on my pc

I need this so that i can combine two or more maps together

by having only GMAPSUPP.IMG I have only one map on my unit

I hope you can help with this

Thanks