Hi, My computer has been like this since I installed my graphics card (x1800GTO PCI-E), but I have ignored the situation since taking components out one by one and still getting the error beeps. Also, the computer starts up properly after about 15-20 minutes of leaving it anyway. The error code is: 1 long beep and 3 short beeps, and on consulting a website, it seems that for an American Megatrends BIOS, this means that: Yet this cannot be the problem as the memory is seated properly, I am sure of that, and after 20 minutes the system starts up fine. Another website says that 1 long beep and 3 short ones means this: With no further description I believe that this might be right, and coupled with another website's description of "extended memory failure", this could be the GPU's memory failing (overeating I suspect). As it seems the error is based on time (leave the PC for 15-20 minutes and it starts up fine), this leads me to believe that it is a overheating/cooling error, with either the GPU memory or something else. As the PC is happy to run for 8+ hours everyday with no lock-ups or other errors, yet cannot restart due to this error, I can't see that there is anything significantly wrong with any of the components (or they wouldn't work at all right?). This has stumped me for so long, Any ideas anyone? Thanks for your time.