system crash after logging in, was fine until ran ndiswrapper

Hello,

I'm a newbie, I used Linux approx. 12 yrs ago and so am very rusty and so my very little knowledge is probably more a liability!...

I installed Ubuntu 8.1 on my laptop using a separate partition and the grub booter. It worked fine (except wireless networking) until I tried to fix the (well documented) problem with the Marvel Libetas driver. I installed the Ndiswrapper and pointed it at the windows driver.
After this the wireless still didn't work, but then the system crashed on shut down.

Now when I start Ubuntu I can get to the login screen, but then it freezes on a blank screen once in.

I'm fairly confident this is a hardware problem but I don't have the skills to identify what I should do.

I have tried reconfiguring the Xserver (in terminal) using the sudo dpkg-reconfigure xserver-xorg
and then sudu /ect/init d/gdm restart
but I'm had no joy either.

I don't know if I can remove the driver / ndiswrapper using the terminal commands, I wouldn't know where to start.

I'd love to get this working again and then have a stab at fixing the wireless problem but first I need to be able to login in as normal!

Any advice would be humbly appreciated.

Ben