Satellite 55 Trackpad

Dear members,
My Toshiba laptop has a funny issue.
I can use my trackpad fine right up to the point where I sign in, at which point it no longer works and I need to use a usb mouse which works fine.

I tried resetting the drivers and rolling back the driver, and it then allows the trackpad to work again fine right up to the point when I turn computer off and on again, at which point it returns to not working after I sign in to my account...

I tried hitting F9 + FN but that does nothing.
I tried taking battery out and holding down power button for 50 seconds then turning back on, and nothing...

What can be done?