IMG files
 

I downloaded all the files for Crusader No remorse from the ISO Cellar. They are img files. I can take them and burn them to a cd like a regular iso file, can't I? Or do I need to convert them to iso files first?

I had that problem back in the day when I'm converting IMG files, but still you can convert it by renaming the .img file to .iso.

I'm fairly sure they're closer to BIN than ISO. Yes, if my memory serves, you can burn a disc using them directly, without converting.
Renaming the file does not automagically change the file contents.

IMG ~ ISO. A renamed file often works.

And if the game has audio tracks...

..... you're screwed.

You can't convert img to iso which has multiple tracks. I suggest get the free burning software ImgBurn. It burns iso,bi,cue,and nrg. and its FREE. Or you can get the share version of Ultra Iso and that practically burns everything.

If you have a program that only accepts ISOs, it's better to - perhaps - have no audio than to have nothing. And by the way, some programs I used in the past were able to access audio tracks on an ISO. They didn't use the ISO 9660 standard even though they only accepted ISOs. They world is strange, sometimes.

Okay, this has gone long enough without any Troubleshooting involved. Moving to Tech Corner.

I wouldn't rely on hacks that may or may not work, get a program that supports .img CD images, there are plenty of free ones.

I can very much recommend ImgBurn too. But it's for making and burning images, that is everything except mounting images as virtual drives. For that I recommend Virtual CloneDrive. Although maybe with the excuse that it's freeware they don't register their driver with Microsoft or something, so Windows will give you a warning while installing it, but I trust it--and you can find it in any freeware directory such as download.com etc.

(I could recommend Daemon Tools too, it has one downside, that it slows down reading CD drives, not only itself but by any other program, as long as the Daemon Tools driver is installed. I learnt this from ImgBurn actually, which gives a warning everytime it finds this driver installed, and I tested and verified it. It's obvious that the guy who makes ImgBurn knows very well what he's doing, and every caveat of CD I/O.)