How do I get scanner to scan system downloaded from Freeware

Trying to program a Uniden BCD996XT. I've downloaded a system from Freeware, but can't get scanner to actually scan that system. I have another county already programed in scanner, which is scanning fine. (Someone else set that up for me.) I needs some advice on what to do with a system in the scanner after it's downloaded from freeware. I'm a neewbie to this, so please keep it basic.