If you have programmes in your Remove Software list, it is quite easy to remove them, provided you are comfortable with using RegEdit. Remember that this will remove the programme from the list, it won't uninstall the programme.
Open regedit (Windows-key+R, type regedit, press enter)
Navigate regedit to: HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall
In this folder you will find all the entries that are in Add/Remove Programs. Deleting a key there will remove it from the list. Do so with care.
If you find your list to have a large chunk of white space in it that's selectable but you can't do anything with it, you have to do some editing in the registry.
Open regedit (Windows-key+R, type regedit, press enter)
Navigate regedit to: HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall
In this folder you will find all the entries that are in Add/Remove Programs. This is where it gets a little tedious. Open the keys, one by one, looking at the DisplayIcon entry. If it has a ,-1 at the end, edit the entry and delete the ,-1. You don't have to replace it with anything.
Open the Add/Remove Programs menu and the white space should be gone. If it isn't, there might be another entry with with a ,-1 at the end.