Helo!

My problem is partially covered in the title. Howewer, there are some details:
2 or 3 months ago, i installed Ubuntu Dapper on my PC (my PC: Abit IS7 motherboard, Pentium 3ghz, Matrox 40GB HDD, Geforce 6600, 1 GB DDR 400 mhz RAM, 17" Samsung monitor)
At that time, Ubuntu installed smoothly, and the system worked without problems. Since then, none of my hardware changed. About 1 month ago, i had to erease Linux, and i used Windows for a few weeks. Then, i downloaded Kubuntu Edgy, and i decided to repartition my hard disc, and make a Kubuntu-Windows dual boot system. The partitioning went fine, but not without some problems.

You see, the Ubuntu liveCD has a graphical interface. Now, this interface has not loaded properly. When i was in the menu of the LiveCD, and i choose "Start or install Kubuntu", i saw the loading screen of Kubuntu's installer. Then, instead of seeing the Ubuntu desktop, where you are able to choose to install the system, i saw a screen that obviously displayed the install screen bad. It looked like it is composed of lines, that are twinkling and are in many colours (the installer didn't do this 2 months ago with the same hardware). I tried Installing with the Ubuntu and Kubuntu Live CDs, and both Dapper and Edgy, and all of them does this. After a while i managed to resolve the problem: it is possible to change the installer's resolution in the LiveCD's menu. When i changed it to 1024*768*32, the installer apperared correctly, i didn't see howewer the mouse cursor, and had to install without it. I managed to do the partitioning, and i was able to install the system. Howewer, when i try to load the now installed system, instead of seeing the desktop, i see this disturbed screen of twinkling lines again. I also see this if i install with Alternate install cd instead of Live CD.

Well, i tought, if setting the resolution by start to 1024*768*32 helped at the installer, it should help now. So, here's a file: /boot/grub/menu.lst I read somewhere that adding this: vga=1024*768*32 to one of the lines (the one that starts with the word "kernel")in this file causes the system to load with that resolution. So i modified the file, and saved it (i did this in text mode using "recovery mode", wich is in the grub menu. Note, that if i, in order to access the text mode hit CTRL+ALT+f1 in the normal (not recovery) mode, the text mode would also appear on the screen as some unidentifiable nonsense).
But it didn't help. The screen was still a twinlking nonsense by start.

So one of my friends said, that the problem must be the nvidia driver, that is installed with Kubuntu. So, he said, that i should give these commands in order to install a better driver:

sudo pppoeconf -this is needed in order to configure the internet connection. I configured the net, so i'm connected automatically at every startup-
sudo apt-get install nvidia-glx

After the driver' installation was over, i hit the reset button, and in the grub menu, choose again the normal mode of Kubuntu. Too bad, that it still didn't get any better.

Any word on what should i do?