just cleaned and rebuilt system the other day, it has been out of commision for a while with unknown error. which i believe i have isolated as a RAM error, the system will not post when two of my four memory modules are inserted, it worked fine with four for ages then one day refused to post, just pushed button and got a lot of noise from my GFX fan. tried the modules individually and two of them are causing this problem, while the other two are working as normal. now heres whats got me thinking, was trying to reinstall windows when i noticed BIOS would not detect IDE optical drive, so i pulled CMOS battery and reset BIOS. drive was detected and windows re-installed, could this CMOS error have caused the memory error at all or are my modules dead? another thing worth noticing is the latency is slightly different to other two modules as well, even though they are same PC2-6400 Reaper 1Gb modules, cheers in advance 
