I have recently purchased a new desktop sprcifically for running FSX.This was basically a heavily discounted PC.I have already replaced the power supply wit a 700w unit.There seem to be some problems with the BIOS,i.e., on boot up,it says there are no disk drives,which is not true,since it boots up OK.My main concern is that if I wish to overclock,I believe I need to upgrade the CPU heatsink/fan combo.I would like some advice on this and general advice on overclocking this unit.I am on a limited budget,but would like to know what I would require at a minimum to run overclocked safely.My specs are in my signature. Ron

Your heatsink/fan needs depend mostly on how hard you want to push it. Since you've already got something in there, you might as well just see how far it'll take you and if you'll be satisfied with it. It probably has the one that came with the processor, which will get you to maybe 3.5 GHz. A reasonably good aftermarket one would probably let you hit about 3.8 GHz, and a high-performance one might even get you above 4.0 GHz. Liquid cooling will let you go well above that and be much quieter than heatsink fans, but at a higher cost. And, of course, you're putting water inside a box full of electronics, so there's little room for error and it has to be checked every now and then for leaks.As for the drive problem, it's unusual, and you may want to do some digging and see if others with that motherboard (or system, since it sounds like it's a pre-built) have had the same problem. Was it doing it before you changed the PSU? Maybe try plugging them into different SATA ports. However, in the end if everything still works right, it may not be something you need to worry too much about.

Being a preconfigired system, the bios will be locked, meaning it cannot be overclocked. Manufacturer such as Asus and Dell do this to prevent damage to the system.