Juan,
Bioware's Neverwinter Nights FAQ site
(
http://nwn.bioware.com/support/techfaq.html#04) tells how to manually
uninstall NWN. These are the steps they recommend:
1.04: How do I manually uninstall Neverwinter Nights? (Back to Top)
If you need to manually uninstall Neverwinter Nights, follow these steps:
1. Delete the folder where the game was installed
2. Remove the entry from the start menu
3. Remove the following Windows Registry key using RegEdit:
MyComputer \HKEY_LOCAL_MACHINE \SOFTWARE \Microsoft \Windows
\CurrentVersion \Uninstall \{7C503E58-B2BC-11D5-978A-0050BA84F5F7}
4. Remove the following Windows Registry key using RegEdit:
MyComputer \HKEY_LOCAL_MACHINE \SOFTWARE \BioWare \NWN \Neverwinter
5. Remove the hidden folder:
C: \Program Files \InstallShield Installation Information
\{7C503E58-B2BC-11D5-978A-0050BA84F5F7}
(where C: is the drive on your system with the Program Files folder)
At this point, there should be no traces of the game on the system.
Hope this helps.