Free Trial Games Causing Problems

I certainly hope someone can help because the knuckleheads providing "technical support" on the website don't seem to have a clue!

Here is my problem: I purchased a PC game, "Midnight Mysteries: Salem Witch Trials" commercially, i.e., I bought it at a store, got the CD-ROM, etc. I really like the game (I'm seriously addicted to hidden object games; is there a cure??) and decided to see what other games the software developer (Mumbo Jumbo) had to offer, so I went on their website, www.mumbojumbo.com, and downloaded/installed a couple of "free trial games" (60 minutes of game play, then you have to buy a registration code). After playing one of the free trials, I went back to play the game I purchased at the store. But, lo and behold, it wasn't there. I figured out (after thinking logically--man did that HURT my brain HA HA) that, for some reason, when I downloaded/installed the trial games, my commercially purchased game was uninstalled/removed from my hard drive. Can anyone explain to me why this would happen and how to fix it? I've already learned one sure fire cure: don't download/install trial games (I KNOW some smarty pants will come up with that; yes, I am a smarty pants, too, with a rather well-developed sense of humor!) Any other ideas?

I contacted techical (non)support and told them basically what I just outlined above: I purchased a ghame commercially and the trial games from the website are for some reason uninstalling my purchased game. Simple and easy to understand, right? Riiiiiiiiiight! The tech who responded sent this reply:Where you have already purchased the game and the CD is working, why are attempting to download the game from the MumboJumbo site? Have you experienced any issues with the game itself? Talk about non-communication!