New to Ubuntu.

Problem description:

Until recently I had Windows on my computer. My hard disk is divided into two partitions.

• On the first one (app. 10 GB) I had my Windows XP
• On the second one (app. 30 GB) I have some data

I tried to install Ubuntu 12.04 on the first partition (the smaller one). Since I wanted to keep the data on my second partition, I chose the third install option.

During the installation process I deleted the data on partition one, created a new partition with the same size, formatted it as ext4 and mounted / on it. The installation continued fine and at the end I restarted and took the CD out when it ejected automatically (it could have been also before the restart).

Ubuntu started but I noticed that my computer was slow. Then a prompt appeared telling me that I did not have the optimal NVidia drivers and recommended to install a specific one. I clicked on the recommended driver, installation went apparently just fine and at the end I had to restart the system again. I did it, Ubuntu started, asked for my password, I typed it, pressed Enter, the screen turned black and remained like that (only the cursor was there and I could move it). I restarted and the same thing happened again.

Has anyone had such a problem before and was able to solve it?

With Windows I always installed drivers from CDs after installing Windows. Are the same CDs going to work for Ubuntu too or I should find special drivers?

P.S. During the installation I was connected to the internet and I agreed on installing updates and the third party software.

In the time before I installed that problematic but recommended NVidia driver I checked that there was between 6 and 7 GB free space on the first partition where I installed Ubuntu.