fans start to spin, then pc restarts

got a new graphics card about a month ago, everything was fine up until the las time i restarted my computer. now, my fans spin, but before they can get up to full speed, the entire thing shuts down and restarts again, until i pull the power. my mobo's LEDs show it as working at full power (green, green, yellow, red are lit) which is what it normally shows when booting up. my graphics card (MSI 460gtx) has the first 2 LEDs (of 6) lit, and is producing beep codes, but i have yet to find any place that can explain either of these. the beep codes seem to be random, and sometimes it doesnt beep at all.

Graphics cards can be hungry beasts, power wise - the only options you really have for testing is to put the card into another PC, or try another Power supply... Good luck..

Sounds like your PSU's choking on the load. What unit are you using?