All of the pieces of the software's uninstaller are not present or damaged. You need to do a manual removal by:
Eliminating entry from Add/Remove Programs list...
1. Reading
How to Manually Remove Programs from the Add or Remove Programs Tool.
2. Removing the software's Add/Remove Programs entry as instructed in #1 at registry key HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\Curr entVersion\Uninstall and noting the key.
And then actually removing the software...
3. Search registry for key in #2 and deleting any related info.
Caution: this is an excellent way to damage computer beyond repair if you don't know what you're doing or paying attention.
4. Delete software's installation folder typically in C:\Program Files.
5. Delete software's start menu entries typically in C:\Documents and Settings\All Users\Start Menu\Programs and/or other users depending on how software was installed.
6. Delete software's other possible data folder typically in C:\Document and Settings\All Users\Application Data and/or other users dependind on how software was installed.
7. Delete software's possible *.ini files typically in C:\, C:\Windows, or C:\Windows\System32, although they could be anywhere.
Recommendations before starting:
1. Do full backup.
2. Set system restore point.
Good luck.