1.) You should always make sure that all older/other gfx drivers are uninstalled..Theres some software for that..I think detonator cleaner or something..
2.) You dont really need a Forceware driver for an mx. A Detonator around version 40.xx or 45.xx should be sufficient.
Cant you also try to install the driver manually ? So instead of starting the exe to install it, just go to system/hardware/gfx card thingy and update the drivers from an extracted directory (if it can be extracted

) :/
And what error do you get anyways ? :l
You could try booting in safe mode and installing the drivers from there ? :O
But thats why I changed from Nvidia to ATI, you always have problems with the stupid drivers
