Post links to the specific maps you had problems with if you want someone to help. But look on the page for each map first. Does it have in icon that says "Installer"? Here's an example:
https://www.gpsfiledepot.com/maps/view/424/The vast majority of maps on this site include an installer. You
do not need cgpsmapper for this kind of map. All that should be needed is to run the installer. In other words, you should
never need to use this tutorial (which is apparently what you were talking about)
https://www.gpsfiledepot.com/tutorials/how-to-load-.img-files-into-mapsource-with-mapsettoolkit/cgpsmapper and mapsettoolkit are used by people who make maps. Some very old maps on this site may require them but I suggest you don't use those maps. The cgpsmapper author discontinued development a number of years ago and his website is now gone. The software can still be found using the wayback machine at archive.org if needed, but you should
not need it.
Most of the problems with maps on this site can be traced to an installer script used by most mapmakers that broke with the introduction of 64 bit Windows 7. Maps using this installer don't have the proper registry keys to be recognized by Basecamp. The "fix" for this is to first install a map that does have the proper keys, then the broken maps should work. Typically we recommend that you remove any maps that aren't working (the same way you would uninstall any Windows program). Then install this map which is known to have a good installer. You don't need to use the map, just install it:
https://www.gpsfiledepot.com/maps/view/53Now re-install the broken maps. This usually fixes things, but if the map still doesn't work then something else is probably wrong and it's may be best to just find another map. Another issue surfaced recently when Garmin updated Basecamp. Apparently some maps only work if they are installed in a specific location. This appears to be relatively rare, based on posts I've seen here.
The maps here were made by many different people with different levels of experience and goals so you can't generalize about them. But they are free and "you get what you pay for". If this is frustrating then you can purchase maps from Garmin who will "hold your hand" throughout the process if you have problems.
However, most people will be able to find free maps that work well if they devote a little time and seek help with problems here in the forums.
Also, you need to understand that Garmin's software license specifically forbids people from making third party maps like the ones on this site. They have never published the specs of their map format and consider it proprietary. However they recognize that free maps help sell their GPS so they just "look the other way". But the cgpsmapper software used by most authors here was reverse-engineered and the author finally abandoned it out of frustration with Garmin's policy. He has tried to sell the source code for a number of years but evidently nobody was interested, so it's just gone now.