Yesterday, I replaced my RAM with 2 sticks (from one package) of Kingston DDR2-667 RAM. My motherboard has a 1066 FSB - but the manual says that it can take either 533 RAM or 667 RAM.I started to have strange crashes to desktop- in FS9 - but also in things like Firefox and Google Earth. Another BAD thing that was also happening was that all of a sudden , the machine was running CHECKDISK on every bootup - and finding weird things. I think that I have read somewhere that faulty RAM causes this.When booting into BIOS, the first (main screen) shows what RAM is installed, including it's speed. When you go to the BIOS screen in which you select the RAM speed for the installed RAM, it has 3 options -- AUTO, 266 (for DDR2-533 ram) and 333 (for DDR2-667ram) . With 333 selected (as my RAM is labelled DDR2-667), the first screen of the BIOS shows that I have DDR2-667 installed) ---BUT!!! with AUTO selected , it shows that I have DDR2-533 installed. I am quite happy with the idea of the RAM only operating at 533 - as that is the "natural" speed of the computer and I was considering only purchasing that anyway.It appears to me that this RAM is not able to run at the 667 speed at which it is labelled - but 533 would be OK by me anyway.I have found a RAM tester that runs from a bootable floppy (MEMTEST86+) - but have not run it yet . Will see how this goes for a while.Any thought on this?ThanksBarry

Yes, CHKDSK can come up if your RAM is bad...happened to me a year ago....Have you tried running just one stick of RAM, and then swapping them out?Also you could load CPUz and see what it says about the RAM

Make sure you installed them in the correct slots. If you have 4 slots and 2 sticks, the sticks should skip a slot (i.e., they should Not be directly adjacent). As long as you skip a slot, it doesn't matter which set you use. Make sure they are installed correctly, set the mem speed to Auto, then run Memtest right away. That chkdsk at every boot sounds like ram problems. You op system install won't last long if that keeps up. Memtest problems = RMA.

Memtest shows no errors - I have set the RAM speed to AUTO in the BIOS and the CHCKDSK at bootup has ceased. But still getting crashes in CPU intensive applications - like FSx.I suspect that this is going to be one of those insoluble ones!! Barry

Just in case, reset the bios to entirely to default setting. Your system is unstable. Get Prime 95 and run that. If you can. get Everest. That's a Real good one and will show voltages and temperatures on a graph line. But get Something that will show those volts and temps while you Prime. Watch 'em as Prime starts failing cores. Maybe that will begin show'n up the problem.

Barry, I was having lots of instability problems when running Crysis and FSX. It turns out that it was my memory timings. I have a gigabyte P35 DSL or something like that, and had it set to auto. For some reason though, it wasn't setting the timings correctly. AS soon as I went in and set them manually per spec, things cleared up.I have heard of lots of others having this problem.Good luck.

Thanks for that - something else for me to try. CPU-Z seems to be indicating everything OK though - timings reported by that programme agree with what they should be.Right now I am running a Prime95 "torture test" - everything OK so far. Memtest86+ runs fine - no errors reported.Barry

Could be wrong, but it seems to me the automatic setting may be based on the FSB speed.1066MT/s = 266Mhz, 1333MT/s = 333Mhz, 1600MT/s = 400Mhz266Mhz * 2 = 532Mhz, 333Mhz * 2 = 666Mhz, 400Mhz * 2 = 800Mhz"Let me help you out. You're cleared to taxi any way you can to any runway you see."