WARNING: don't start doing any of this right off the bat if you're a n00b and don't understand any of it. Read through the whole thing if you don't want to risk messing up your computer.
Yesterday I installed a program which had no uninstaller, so I had a bit of trouble with it after realising this thing was useless (have I mentioned it didn't even had an uninstaller?). I couldn't remove it in Add or Remove Programs, Revo and IObit Uninstaller's didn't work either, because all of these need the uninstaller. So I did it MANually.
I don't recommend doing this at all, it should only be your last resort. I don't even know if this is a correct way to uninstall a program, but I've had no problems so far. You won't be surprised, it's pretty obvious what I decided to do. I deleted the program's installation folder in C:\Program Files. That's it.
Of course, it won't let you delete everything, because some of those stupid .exe will still be running. What you have to do is to forcefully terminate them. Open up the Task Manager (if you're a complete n00b and don't even know what that is, hit the Ctrl+SHIFT+ESC combo to bring it up. There it is. Congratulations, you've just learnt a new combo). Now go to the Processes tab if you're not already there. There's a button/check box on the bottom left corner, it'll show you the processes running for all users once you click it. So click it.
Now you're probably staring at your monitor going "wtf", if you're a n00b. Next you have to know what process to terminate. First make the list steady by clicking on Image Name. Now scroll the list and look for the .exe that has the same name as the one you can't delete. Select it and hit the End Process button on the bottom right. Once successful you'll be able to delete the .exe from the folder. Clean up the registry afterwards if you want, using something like CCleaner or Wise Registry Cleaner.
more WARNING: don't mess around in the Task Manager, n00b, and be sure about the process you're terminating. Don't terminate anything else except the one you want to get rid of. Hopefully you won't find many programs without an uninstaller, so again, this is your last resort.