Answer
Moving programs from one drive to another on the same computer is a lot more complicated than just moving the files in the game's folder to the same folder (or a new folder) on a different drive.

First, while they are called "games" they are, first and foremost: programs, like any other program. When you install a program (in most cases) there are registry entries made, start menu shortcuts created, folders created and other changes taking place on your system. Simply moving folder "A" containing the programs files on C: drive to a new folder "A" on another drive can leave your game or program useless. Additionally, when you try to uninstall it, the uninstaller will not be able to find all the files associated with the program, because you moved them. Moving programs, even "games" is a complicated and delicate task. Basically, you shouldn't do it unless you really know what you're doing and make all the necessary changes to the registry. There are programs like Partition Magic  (once a PowerQuest product Partition Magic was bought out by (UGH!) Norton (Symantec). Luckily for us and you, however, the program remains the same as it was when PowerQuest made it. Trying to move programs from one hard drive partition or physical drive to another manually is a task that even the most experienced computer users don't like to do. It can result in failure. It's a complicated process. And can leave you with non-functioning programs and no really easy way to uninstall them.

The correct way to move programs would be to uninstall the program using its uninstaller (or Control Panel/Add or Remove Programs) and then re-install the program on the new drive. If you have settings and preferences that you'd like to save you can try creating a folder on the destination drive, copying the files from the program's current folder and pasting them in the new folder on the destination drive. Do this before you uninstall the program. Then when you re-install the program, install it into the new folder you've created on the destination drive. Sometimes this works and sometimes it doesn't but it's worth a try if you have a lot of personal options and preferences set.

Please note when re-installing software on a new drive, and it required you to register it with a key, you'll probably need to re-register it after re-installation. So make sure you have your registration key handy during re-installation.

As for the files you cannot remove using the uninstall feature or Control Panel/Add or Remove Programs? About the only way you can get rid of them after you've moved the program is to do simply delete them. Before you do, however, we'd recommend you try reinstalling the original program into the new folder(s) you've created on your larger hard drive. Maybe, just maybe, with some luck the files you have remaining are your personal settings and preferences -and if so, might save you time when you configure the program after you've installed it. It's sure worth a try.