[coover]

Using Vista Ultimate ...

I attempted to download some files via Microsoft Update and after about 10 minutes the download had not started. So I attempted to close Update, expecting to be able to go back later and make the downloads.

Update did not easily close and I had to open Task Manager and force the close. Now, when I attempt to open Update, I get a blank rectangle in the middle of my screen and the round circle, which indicates to me that it trying to open the application. Again, I waited about 10 minutes and Update never did fully open. I, again, had to force it to close with the Task Manager.

[RabidAardvark]

Try shutting down windows Updates, Background Intelligent Service and Cryptographic Service using services.msc then rename SoftwareDistribution folder (in \windows) and catroot2 folder (in \system32). Restart the 3 services.
Next using msconfig, under General tab, choose Selective Startup & uncheck Load Startup Services. Under Services tab choose Hide All Microsoft Services then Disable All.
Reboot & try to update, if it works, one of the startup services may be causing conflict, put them back 1 at a time & retry (very tedious).
This has worked on 1 system for me & failed on another.