Crossfire installer won't run, makes Windows unstable and slow

Hi everyone
I am running Windows 7 Ultimate (64-bit and the RC, not the retail version)
Crossfire will download, but I can't install it. I go to the file and double click on it. After that, the progress bar starts moving VERY SLOWLY and nothing happens. My computer is then unstable and most programs crash until I restart the program. UAC does not make a difference if it is on or off. I have Microsoft Security Essentials for my antivirus.

One thing, Malwarebytes detected: HiJack.DisplayProperties

My PC:
- GIGABYTE GA-MA780G-UD3H
- AMD Phenom X3 8650 (Triple core, 2.3GHz) (don't laugh )
- 1GB DDR2-800 RAM (used to have more, but it died xD)
- 500 GB Hard Drive (I forgot the brand)
- 2 DVD-RW drives
- NVIDIA GeForce 9500GT 1GB
- Integrated Sound
- Windows 7 Ultimate 64-bit Release Candidate

EDIT: I can get a video for you if you need it. And BTW, I can install other programs, like Ventrilo
Thanks