how to desinstall starforce ?

[genjutsushi]

i've installed gangland and desinstall it yesterday but when i reinstall it and i enter the cdkey, it says that the key is wrong.
i've installed it with a mounted image in alcohol with rmps emulation option on and all my ide cdrom unplugged, like the first time
i've cleaned my registry but it's the same thing and impossible to delete the keys of starforce

please help