For ages now I have have been prompted when I loaded Live Writer that there was an upgrade available, and every time I tried it get it, at the end of the install it failed and rolled back. As I did not have time to dig into it I just used the older version.
Well today, due to upgrades in our LAN, I need to upgraded Live Messenger and as this is of part of the same Live Essentials 2011 package it not unsurprising I hit the same problem. A bit of experimentation showed the issues was that the upgrade was not able to remove the old version. If i tried to remove it via Control Panel it failed with a 0x4004004 error. In the error log I saw
Product: Windows Live Messenger — Error 1402. Could not open key: UNKNOWN\Components\A49B6681220C2EA49826913B104EE03B\B55DF58AB1984134795AAE690CDB085B. System error 5. Verify that you have sufficient access to that key, or contact your support personnel.
A bit of web research show this seems to be related to 32/64bt issues and maybe debris from the beta version of Live Writer.
The answer was to use Windows Clean Up Utility (remember this is take no prisoners tool so use it with care) and remove all the package with the words ‘Microsoft’ and ‘Live’ in their names. Once this was done the Live Essentials 2011 installer was happy to do a new install, and it even remembered my blog settings!