If you remove an installed program and its files by deleting the files, it may still be listed in the Add/Remove Programs in Control Panel. To remove it from the list:
1. Start the Registry Editor
2. Open HKEY_LOCAL_MACHINE \ SOFTWARE \ Microsoft \ Windows \ CurrentVersion \ Uninstall
3. Delete the program entry here
4. Close the Registry Editor and restart Windows
You can use TweakUI (you can find it on your CD-ROM in the \tools\reskit\powertoy folder) to clear the Add/Remove Programs section.
You can also use my Tweaking Toolbox for Windows, one of it's functions is to remove programs listed in the Control Panel's Add/Remove Programs Section.
For more information & free trial, check the Tweaking Toolbox for Windows pages. 
Removing Programs listed in the Control Panel's Add/Remove Programs Section