Another Post on this subject: http://www.computing.net/windows2000/wwwboard/forum/41160.html Oh and FYI: "Disable" is NOT a Windows 2000 command. I have had this mup.sys problem for serveral months now. My system will boot but only after 1 1/2 hours of waiting on the boot screen. I finally was able to do a rebuild of that server today and ran accross where the issue resides with my system. I installed Windows 2000 server, SP3, IE6 w/sp1, then the ton of other patchs and "Recommended Updates". The only Recommended Updates update I did not install was Windows Media 9. The first time I did the installation I also installed the MS drivers. Then after reboot BANG! It locked up again. So the second time I didn't and all is running well now. The drivers I didn't install are: ***I highly suspect the Video Driver*** ATI Technologies, Inc - Video Ati Technologies Inc. Display Driver Version 5.0.2195.5012 IBM - Storage Ibm Corporation Scsiadapter Driver Version 4.80.26 Analog Devices Incorporated - Sound Analog Devices Media Driver Version 5.12.01.3039 Intel Corporation - Networking Intel Net Driver Version 6.1.3.0 Adaptec, Incorporated - Storage Adaptec Scsiadapter Driver Version 6.1.530.201 IBM - Storage Ibm Corporation Scsiadapter Driver Version 4.84.01 Now if somone can pin down what driver that would mess with mup.sys that would be nice. Thanks, RunningRhino

Are you running a Asus/VIA board, like the KT7A-RAID I have? I suspect so. Did you install the VIA/Hyperion update? Or are you running a RAID system and install the Highpoint update from VIA? Or the USB filter patch? Cos I did one of those and wham, the old MUP.SYS hang is back. Disabled the USB & the RAID and voila I can boot. I suspect it's either VIA's 4on1 Hyperion drivers or the USB. WTF that's got to do with a network driver, I don't know... Tim