Repair IE8 on XP and “ordinal 421 urlmon.dll” error — Last resort [Fixed]
OK, so you’ve removed malware preventing Windows from starting, check! Or, maybe you just botched an IE8 upgrade. So now you notice IE8 isn’t working… well, maybe you can get to a webpage, but you can’t use the IE toolbar or get to other settings, such as internet properties (i.e. inetcpl.cpl doesn’t launch.) — or maybe it just doesn’t work at all……. Maybe it’s not even IE8 but it’s IE7…… or maybe it’s so foobar you just can’t determine what version it is.
Maybe, just maybe, you tried to reinstall (or upgrade to) IE8. It uninstalls the previous [unknown] version of IE and wants a restart. You restart, and explorer.exe crashes, and maybe most things you run give an error like ordinal 421 urlmon.dll… maybe the cryptographic service (cryptsvc) won’t start so you can’t try another reinstall. Naturally you’ve tried re-registering dlls, sfc, copying over files, and other troubleshooting techniques to no avail. Well if you’ve got this far you need to do a system restore. Safe mode won’t do that? Try Microsoft’s ERCD or some other WinPE based CD with system restore functionality. But now your back to SQUARE ONE. Now you try to reinstall IE8 again, but it fails… You’ve already tried the desktop shortcut it creates (in another browser of course) http://support.microsoft.com/kb/949220 and no luck.
System already has XP SP3, but have you ever noticed that you cannot uninstall IE if you installed SP3 after IE… Hmm…..
Solution! FORCE-REINSTALL XP SP3 to prevent the IE8 installer from trying to uninstall a previous version! Yep. Get the redistributable download of XP SP3, run the setup with these command line parameters: /overwriteoem /nobackup /passive /forceappsclose /forcerestart (and note if you really want to waste some time you can skip the /nobackup switch, but if this doesn’t work you’re doing a repair or fresh install of Windows, so why waste time with a broken system-state backup?)
Now that you’ve reinstalled SP3, fire up the IE8 setup again. BAM! This time IE8 setup strangely warns you something like “hey, you just installed SP3 so you can’t install me later, proceed?” Uhh, whatever, but sure! Now setup proceeds WITHOUT attempting to uninstall a previous version of IE and restart, it just installs which is all you wanted in the first place. One restart later and Windows + IE8 purs like a kitten, windows update works, everything is just peachy.