I can't install cf!

Same thing happens to me

When the CF_Downloader reaches 100%, it says "[Failed to start process]".

Here's some info on my computer:
-Operating System: Windows XP Service Pack 3
-Processor: Intel Core i5 760 (Lynnfield) @ 2.80Ghz, but with Game Booster it reaches 3.4GHz
-Motherboard Manufactured By: ASUSTek Computer INC.
-Motherboard Model: P7H55-M PRO
-Graphics Card: ATI Radeon HD 5670

Dunnoe about DirectX tho