I'm trying to install Ubuntu on my PC ..
but it simply hangs every time at the same place after i choose to "install linux on my hard disk" ... with a black blank page ..
Your spec show that this is a some what new system, what Ubuntu version are you using? If this is a little bit older version it may not support the video card you have. I have a system of about the same specs as yours and I could not install 7.10 Ubuntu, I had to use 8.04. I had the same problem with Debian, I couldn't install Debian Etch I had to use Debian Lenny (Then testing) before it would see my video card.
Another thing you can try, when you get to the option page press F1 and try some of the boot options. Also you may even try the command line installer if they still offer it.
[complaining here] The lattest version of Ubuntu 8.10 didn't even give the option to install/not-install Grub to the MBR that bugs the heck out of me. [/complaining here]