Messed with desktop settings, screen is black after login! HElp

[Kriskrosa]

I installed Mandriva 2009 free on an Acer laptop. It worked great. Then I started to set it up. It was going flawlessly.

Then, I turned on extra desktop "effects", it asked me if I wanted the new setting, I clicked yes. Screen went black, I can see some lines, but everything is black.

When I boot the laptop, I get to the login screen of Mandriva, This looks normal. I select my username and type my password, And log in. Then, I am greeted with the same black screen with two or three lines going over.

How do I restore the previous desktop settings?
I tried the safe mode but I just got a command prompt, and I dont understand how to do much from there yet. I also tried the rescue disc which was useless.

Any help here?

[Loy Glenn]

from the safe mode command prompt try "startx"