My daughter is running Vista Home Premium on a 6 month old and up to date Sony Vaio laptop.
I am relying on her for this information and it is a bit vague. I believe she is running Reader 8 and was prompted to download updates which she did. She was then eventually taken to a page:-
Configuring Updates: Stage 3 of 3 - 0% complete. Do not turn off your computer.
The % does not change and after a whicle "Welcome" appears on the screen and then immediately "Shutting down." The computer then restarts itself. It then goes back to the Configuring Updates page and continues in this loop. Forcing shutdown and starting in Safe Mode or Command Prompt takes you to the same page and I can't find a way of logging in to be able to delete the Adobe Reader to start again.