Erratic fan speed on CPU causes WinXP to immediately shut down the machine. Can not stay in WinXP for more than 120 seconds before XP begins the shutdown procedure. Fortunately, I have a dual boot system and am writing to you now from Win98SE. Downloaded the latest version of the Intel Active Monitor Utility (v1.16 released 4/22/2002) and installed it in Win98SE. Shows all Cooling Temperatures and Power Supply Voltages stable and within acceptable operating ranges. The problem arises with the fan attached to the CPU. The fan speed will be constant at 5,120 rpm for a few seconds and will then drop to 4,915 for a few seconds and then return to 5,120. Periodically it will pop up to 5,342 for a second or two and then return to 5,120. No other fan speeds have been observed in over twenty hours of operation. Also, in over twenty hours of operation the temperature in the Processor Zone has been constant at 36 Celsius and the System Zone has been constant at 41 Celsius. The apparent problem is that when WinXP sees the fan speed drop, it automatically goes into system shutdown mode. I can access WinXP in Safe Mode, without being shutdown, and can run the services.msc and gpedit.msc utilities. My problem is I have no idea what services, sys drivers, or DLLs to disable to allow WinXP to continue without automatic shutdown. Removed standard 250 watt power supply and replaced it with a new 300 watt but without any change in the above conditions. Will get this fan replaced/repaired at some point, but in the meantime, need to use WinXP. Would greatly appreciate any suggestions.. Machine config: Intel VC820 mobo Intel PIII 800MHz with Intel fan attached. 256 MB RAM (RamBus) Dual Boot (Separate partitions) WinXP Pro and Win98SE 40, 20, 20 GB Hard Disks

I do not think XP is sensing your fan speed at all. Fan speed and temperature shutdowns are set in your BIOS. Check your BIOS settings.

Yes, and that small change in speed should not be enough to cause a problem. My fan speed varies some too.

I agree. That fan speed variability you describe is absolutely normal. XP does not monitor fan speed and shut down. I think you have some other problem. What made you think it was the fan speed?

The reason I believed the problem to be the fan speed was the fact that on the first two occasions, a message poped up saying "Your system fan has slowed or stopped. Details will be available on your next logon" Details were never available and now the machine simply shuts down without any message or warning. The central question now is: How to stop WinXP from automatically shutting down?

disable the Fan monitor in your Bios. What Motherboard do you have? Also consider changing the fan. I know in many computer shows there are fans galore. Heatsink fans are interchangeeable (just dont let AMD or Intel know) I have a copper cooler with a globalwin fan, took the delta off and swapped until i can find a quiet yet powerful fan to use.

I experienced the exact same problems with XP on an MSI board with an AMD 1.6GHz processor. Of coarse, when things don't work, everything becomes suspect. I too noticed crashes at suspicious fan speeds. I tried all sorts of things to keep XP running for more than 2 mins,... Finally, I decreased processor and bus speeds. This enabled me to keep running for more than 2 mins (about 10 mins.) Just the time I needed to update XP. But after the updates, I still had problems. (OH, I think one of the updates included drivers for AMD chips.) I assumed there was something wrong with XP because I had no problems installing and running Windows ME. (an assumption I still maintain.) However, I finally determined that I was a victim of Electromegnetic Interference. I customized my BIOS; modifying the standard (not high performance) default by adjusting the CPU FSB Clock to 133MHz and the Spread Spectrum to +/-0.25%. These BIOS changes give me the processing power I originally wanted and reduces the EMI (Electomagnetic Interference). I haven't experienced any crashes since I made these BIOS changes. I still feel there is definitly something going on with XP, but all I can conclusively state is that I was plagued by EMI. Hope this helps.