problem installing unreal tournament 3

So I've downloaded the demo twice from gamespot and each time I try to install in a black (DOS) looking screen pops up and then disappears and nothing happens. I am running windows xp sp2 AMD X2 4200 2.4GHz, 2GB DDR2 memorey,250SATA2 Samsung HD and EVGA 8600GT.

Does anyone know why it is doing this and what I can do to fix it?

thanks!

anyone?

Hi

try this

Click on Start > Control Panel > Administrative Tools -> Local Security Policy
Right click on Software Restriction Policies and select New Software Restriction Policies from the popup menu.
Left click on Software Restriction Policies, right click on Enforcement, and select Properties from the popup menu.
Under Apply software restriction policies to the following users: click All users except local administrators. Click the Apply and OK buttons - you should now be able to install the UT3 Demo