Vista is stuck on the "configuring updates" screen

15 Nov 2011
Needed this asap and google helped

To resolve this - get to a command prompt:
The command prompt may display as "X:" - if it does, type "C:" and press enter (changing the location to the boot drive).
Change directory to the "C:\Windows\winsxs" folder by typing:
" CD \ " (press Enter)
" CD \Windows\winsxs " (press Enter)
Rename the file named "Pending.xml" to something else by typing:
"ren pending.xml" (press Enter)
Run regedit by typing "Regedit" and press Enter.
Search for the entry with this description: "Advanced installer need resolving"
and delete it.
Search for the entry: "Pending.xml identifier" (which will be 2 lines or so after the first one) and delete it.
End the Regedit and reboot. You should be OK.

It's working!!