Hello to all!
I have accured a very annoying error with several unreal engine games.(UT3, Mirrors edge, Gears of War)
When I try to run them, the splash logo or what with the game picture appears, after that it comes out with an error saying: -game name- has stopped working:

Problem signature:
Problem Event Name: BEX
Application Name: -game name-.exe
Application Version: 1.0.0.0
Application Timestamp: 494014da
Fault Module Name: RFNEW.dll_unloaded
Fault Module Version: 0.0.0.0
Fault Module Timestamp: 4329f600
Exception Offset: 213421a0
Exception Code: c0000005
Exception Data: 00000008
OS Version: 6.1.7600.2.0.0.256.1
Locale ID: 1038
Additional Information 1: 0a9e
Additional Information 2: 0a9e372d3b4ad19135b953a78882e789
Additional Information 3: 0a9e
Additional Information 4: 0a9e372d3b4ad19135b953a78882e789

I have all the reqs of the game, my computer is an AMD 3500+ 2200MHZ with MSI motherboard, Ati Radeon HD 4650 512 mb, and 2GB RAM, with windows 7.
With XP SP 3 when I got the error, I just clicked into the black window behind the error message and it worked just fine. With 7 I cant do anything.
PLEASE HELP.