system info:rom ver.17C6.YF.S1.6.20/Processor:ATLASIII/RAM size 64mb/MLC size:976 mb/software ver. v2.0.0.5.28\ Invion V7.0.24.137.1 TMC Inactive Destinator technologies inc. Navteq on board....i would like to update maps and system. thanks in advance

From the specs it looks to be a YFATLAS clone but with different firmware as your Rom version is not originally.
But that does not really matter, you should have a settings button or a button labeld "Nav Path" somewhere.
You can install Igo, Primo or whatever you want on a SD card (please follow the instructions for the software installation) and simply change the path to the navigation software on your device.
If you want to use more than one program you might find a "favourites" button on your device, with that you can locate EXE files on your system and create a "link" to start it from.

Other option for that would be to use a customised menu or "unlock" to get some games and additional software as well.
Please stay away from MIOPOCKET as it will render your device to brick, same goes for other "unlock" systems that modify your registry and Windows CE system.
We have some menu alternatives in the forum if you're interested.