Try to install all the windows updates and try installing MPLAB again. In the release note it says it is supported on Windows(r) 2000 SP4. I have seen some software fail to work if all the updates are not applied. On 7/26/07, Roy wrote: > Error 1904.Module C:\Program Files\Microchip IDE\Core\Editor\MPUScrcvw4.dll > failed to register. HRESULT - 2147220473. Contact your support personal. -- Chetan Bhargava Web: http://www.bhargavaz.net Blog: http://microz.blogspot.com -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist