Probably the easiest way to delete the other option is to download EasyBCD. You can remove the other OS option. You can do it with BCDedit if you want to try.
For right now, open an administrative command window and type bcdedit. It should show what is in the Master Boot Record and the BCD store, which is where the OS options are stored.
We have someone else having problems restoring XP as an OS, so could you take a snipping tool shot of the resulting information and post it, make sure anything that might be personal be covered.