I am almost assembling custom pc for around 2 years. I am having quiet a good knowledge about putting different hardware together and configuring the operating system. I am working on a system which has E6700 Quad Core CPU, Abit AW9D-Max chipset, 2GB RAM and ATI Radeon X1800 XL GPU. It looks like everything is working fine. I can access the bios screen and change settings. After installing Windows Vista 64bit I am getting regular bsod. The system just did not stand stable. First the BSOD appears giving a error - A Clock interrupt was not received on a secondary processor within the allocated time interval. I saw this error first time and not able to under to which hardware it is related. I had checked by changing the RAM and updated bios also. But still nothing worked. The client needs Vista 64bit only. What is the issue with the same. How can I stop this crashing.