First, simply removing them from the Program Files folder doesn't uninstall them, so it's best to attempt a correct uninstall first..
If they don't show up in the Control Panel/Add-Remove Programs, then check in the Programs menu to see if there is an uninstall link. Click on Start-All Programs-YourProgram (where "yourprogram" is the one you want to remove), then look to see if there is an uninstall link listed there. If there is, use that.
Next, check to see if there is an uninstall.exe file in the actual program folder you want to remove.. RIGHT click on Start, choose "Explore" from the little menu, then, looking on the left side of the screen, scroll down and click on the + sign next to "Program Files", then double click directly on the "YourProgram" folder to display all the files in that folder.. Look on the right side of the window and see if there is a file named, "uninstall.exe" or "Unwise.exe", or something similar.. You may be able to uninstall from there.
And if you still can't find and uninstaller, then YES, you can remove the entire "yourprogram" folder and it will no longer be on the computer.. The problem is, you may have a registry entry which still attempts to load the program.. If you get errors, you'll want to do registry search to eliminate such remnants from the computer.
Hope this helps.
if the program does not exist in the Control Panel and/remove folder? I have a number of programs that I would like to get rid of that aren't in the Add/Remove program.