crossfire requirements are:
CPU
Pentium 4 - 1.5GHz
Pentium 4 - 2 GHz
MEMORY
512mb
1GB or higher
VIDEO CARD
GeForce 5600
Or Equivalent Class
GeForce 6600
Or Equivalent Class
HARD DISK
1.2GB

SYSTEM
Windows XP, Windows Vista and Windows 7

DIRECT X
C 9.0 Or Later

INTERNET CONNECTION
Cable / DSL Or Better

My netbook aspire one is a D255 1.5 ghz, 1 gb ram, 250 video memory