Does AH alpha require a 64 bit version of Windows?
Reason I ask: Europe 2015 hard crashes my machine after it loads, sometimes within seconds. I've checked the Commit values and they are 1.4 GB while it's (briefly) running and the system has plenty of free RAM. The crash goes to black screen and then a reboot; it happens very quickly every time the Europe 2015 terrain is loaded. Ndisles crashes similarly, but very infrequently.
E8400 @ 3GHz, 4GB RAM, Radeon HD7870, Win XP 32 bit, 4K textures, 1920x1080, everything maxed except Environment at 0 and Post Lighting disabled.