I see that you have mentioned in your configuration "Configuration: Windows XP / Firefox 19.0". Use the following steps to remove one of the Windows XP:
1. Boot to the Window XP you want to keep.
2. Right-click on My Computer, and select Properties.
3. Move to the Advanced tab.
4. Under Startup and Recovery, select Settings.
5. Click edit.
6. First save a copy of the Notepad file which opens 'boot.ini' just in case you make a mistake.
7. You will see lines such as the following:
[boot loader] timeout=30
multi(0)disk(0)rdisk(0)partition(1)\WINDOWS="Microsoft Windows XP Professional" /fastdetect /NoExecute=OptIn
8. There will also be a line for the other OS here under [operating systems] which reads similar to the following: 'multi(1)disk(0)partition(#)...'
9. Check that your default line points to XP, as it does above. Then erase the line with the other OS. Please note that the entire line of code to be removed may be more than one line in Notepad. Save the file.
11. If everything looks correct, you can delete the folder associated with the Other Windows XP that you wish to delete.
If any mistakes occur, load back into your existing OS, copy the old boot.ini over the modified one, and try again.
Windows 7 gives you a more easy way to remove this. Click "Start", click "Run", type "msconfig" and hit enter. If a UAC (User Account Control) window appears click "Yes". In the next windows that opens, select "Boot" from the tabs at the top, you will see the two Operating Systems listed here. Click on the Operating System that you want to remove and click "Delete Button".