Can you launch
ANY exe's or is it just happening to JTCS? Did you replace the harddrive or someone else? If you did it, go back in and check all the connections. Make sure the video card and RAM chips weren't loosened. Has your computer been bombing? Blue screens? Have you tried starting your computer and opening the game in safe mode?
Hardware could cause this, software, viruses/malware. Really hard to diagnose. If you want to go with Jim's suggestion, you could try ccleaner (
http://www.piriform.com/ccleaner). It's pretty good, but I'd be surprised if it helps. Worth a shot though. The free version will try to get you to install a toolbar, so just say no to that. After that, run the defaults and make sure you make a restore point, just in case.
I'm leaning toward a problem with your operating system caused either by a corruption or a virus/malware. It sounds like the way it's handling associations is messed up, but I'm just guessing. Again, just the game or other exe's? If just the game, then it's probably not that.
Lastly, if this is just happening with the game, try uninstalling it. Look for any remnants that might have been left behind after the uninstall and delete them.
Then run ccleaner removing temp files and cleaning the registry. Run the registry cleaner several times. Reboot and reinstall the game.
Good luck. Let us know how you make out.
Dave
Resolve then, that on this very ground, with small flags waving and tinny blasts on tiny trumpets, we shall meet the enemy, and not only may he be ours, he may be us. --Walt Kelly