CoH powers down my machine?
the thing i think could be happening is when you increase the graphics it may be causing an overheating issue. my computer was overheating and doing that same type of thing for unreal tournament 3

It may be the same power supply, but does your new board and/or video cards, or other hardware you might have take more power than you had before? Besides overheating, I've seen that happen when you are simply drawing too much power as well.
my motherboard comes with some diagnostic tools and i ran em and found that for some reason my power supply fan isnt running at all oh joy me, its brand spanking new!
Bonnie and her bunny
Arc ID: 59406
The Trash Came Back
Arc ID: 350303
It says it isn't but have you visually checked for it ?
Combat Kangaroos, Justice Server. First 50's
Jirra Roo Plant/Storm/Stone/Musculature Controller
Combat Kangaroo Rifle/Energy/Mace/Spiritual Blaster
Kung Fu Kangaroo Martial Arts/Reflexes/Body/Spiritual Scrapper
Tribal Arc Shield/Elec/Mu/Spiritual Tanker
I have had this computer for a while now and have recently changed my motherboard and replaced my power supply. today after doing a fresh install of Windows and new drivers for everything and new install of CoH I fired up the game and after upping the graphical settings to max the game either freezes the entire system or the computer simply powers down.
My MoBo is an ASUS P5N-T Deluxe
2.75 GIGs of RAM (using 32 not 64 bit ver or it would recognize more)
2x Nvidia GeForce 8800 GTX video cards
Ultra 3 1000W power supply.
I have never encountered an issue like this before using these cards. the previous power supply is the exact model. the previous MoBo is a ASUS P5N32-SLI Premium. AFAIK that should be a factor though.
Bonnie and her bunny
Arc ID: 59406
The Trash Came Back
Arc ID: 350303