Yesterday I removed a few programs I was not using and ran Spybot to check and clean my PC. Somehow I broke QB 2004 in the process. When I tried to open it I got this message:
an unrecoverable error has occoured exception MSXML could not CoCreateInstance HRESULT=80040154 thrown with error code-2147221164
Function: ADR::Repository DoInitialLoad
File: ..srcRepository.cpp
Line: 81
After some investigation I found out that I was getting a non-serious error with IE about “cannot read properties at this time” and the Windows Update service was failing with a 0x800A01AD. After some research and some failed guesses I fixed the problem by re-registering msxml3.dll with the following command, "regsvr32 msxml3.dll". This must have been inadvertently been un-registered when I uninstalled Salesforce.com’s sync software.