cant install

[taye001]

I tried installing the game many times. each time, it hits 100% percent Then it switches to a screen that says.. It says

you computer has not been modified, the wizard stop unexpectly
you can try to reinstall the game later.

I tried, disabling norton's all firewalls. I tried downloading the game from 2 sources. fileshack and hellgamers.

Both installation say the same thing.
I now for sure that I have enough space on my computer.

What going on? I want to try this game out. Been up 2 days trying to install this game.