That is why I was vague. If you did not know, you would ask for more info.
Ok messing with your reg can be dangerous, but this is a simple fix.
Open the run dialog in Start, or use the key combination. Windowskey+R. then type regedit.
You will notice the hives.
They are:
HKEY Classes_Root
HKEY Current_User
HKEY Local_Machine
etc..
You want to go to the one listed as the HKEY_Local_Machine
Then expand that, by hitting the little +
Once you do that, navigate like you would in Explorer. Following the path I have given. Pretty much when you see the folder keep expanding until you reach the end of the path..
HKEY_LOCAL_MACHINE|SOFTWARE|Microsoft|Windows|CurrentVersion|Uninstall
HKEY_Local_Machine then locate the Folder listed as SOFTWARE.. Then keep going until you see
Unistall. Once you reach the end of the string. You should see the iTunes key. That is the one you want to delete.
You should be logged in as a admin while doing this. Since a limited user cannot do the neccesary changes.
Set a restore point prior to doing this. If you have restore disabled, enable it. That is the just incase you do something wrong. I believe if you do find the iTunes key it will not do any harm. Though any time you mess with the reg it can hose your computer. Hence the restore. There is a way to backup the reg, but restore is just as easy.
Once you do remove the key or keys relating to iTunes. Do a restart then check and notice it is gone from the list. Since that is where it sits in the add/remove list.