24.05.2009, 06:24
It could very well be the PSU. 500 watts really is not very much power for modern computers and generic PSU's are notorious for not being capable of supplying their rated power. I would suggest installing a high quality PSU of 650 watts or greater. 650 sounds like a lot, but it keeps the PSU from having to supply its maximum rated power, making the PSU run cooler, last longer, and can improve system stability.