Windows Update Installation Problems. Help!

I am having problems with Windows updates. After installation of 74 downlaoded updates I get a message after restart saying "Failure to configure updates. Reverting changes". I have tried manual installation and I get the following error codes for two of the 74 updates: Code 643 and Code C355. Help!

First, never install 74 updates in one updating session. If one of the updates causes an installation issue then all of the updates may fail to install.
And, if one of the updates later causes stability or usability issues after 74 updates have been installed, you would have to uninstall all of them to find out which one is the culprit.
Suggest you install them in groups of 5 or 10. Yes, it's a PITA, but it's better to be safe than sorry.

Please post the KB numbers of the 2 updates which are failing to install.