Windows – the path for the “Personalize” control panel in Windows 7

TweakUI has an option to "Rebuild icons" - have you tried that?

Here's a standard set of icons:

If you are not missing any of the system icons above, and you don't know what the phantom icon is, then by all mean get rid of it! TweakUI can hide it so you can forget it. You could possibly succeed in a hunt for the CPL file in your Windows folder, but I don't know if deleting the CPL is enough. There could also be registry entries somewhere.

You can get some clues as to where an application lives, by looking at where it's uninstaller is located.

Windows stores the list of uninstaller locations in the registry. You can use Regedit to go to HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall.

That registry key contains a whole lot of sub-keys with GUID names (big long strings of seemingly random letters and numbers). Use Regedit's search function and set it to look for the name of your program as it appears in the "programs and features" list of installed programs. (Un-tick keys and values and just leave data ticked).

Once you find the right sub-key, you'll see a bunch of values for your program. One of them will be called "UninstallString" and may point to the executable or DLL that is used to uninstall the software (or might pass a file location as a parameter to MSIexec or RunDLL). Depending on where the application's uninstaller lives, that information might give you the clue you need to find the rest of the application.

There are other bits of information in the registry that can help you too - See more info from Microsoft at https://msdn.microsoft.com/en-us/library/aa372105(v=vs.85).aspx

Typically programs that don't list an install location will have installed themselves in a number of places around your disk though, so it's best to use the uninstaller if you can.