Welcome to TSF, Joeyun. ^^
It sounds as though the program is malicious in nature. Programs like this need to be forcibly removed using a non-related method (manually deleting the files and registry entries). This can be accomplished easily using a third-party software like Revo Uninstaller, as Old Rich recommended. I use Revo, myself, for managing out-dated or unused softwares on all my systems.
You could try your hand at CCleaner
. It's been a few years since I've used it, but I believe they also have a more thorough uninstaller.
If you feel like paying for a bit more expensive of a solution, but one that comes with a lot of side-benefits, check out TuneUp Utilities
. I had a falling out with them a few years back when their yearly upgrade didn't quite meet expectations, but I still believe they have a great product.
The last suggestion, from me, would be to find a source that has covered this exact issue, and follow the removal instructions from there. If all else fails, we could always whip up a dummy machine and create this step-by-step instructions, though they'd probably be very lengthy and require manipulation of your registry (not recommended for beginners/intermediates).
I hope we've helped. ^^