Vista - Vista can't get to desktop or safemode

-- I need help describing my problem. What is the name of the screen that
you see with the various users listed as Vista Boots?

I need to know that because whatever the name of that screen is, it is the
last screen I see, for about 5 or 10 seconds, before the computer I am
working on shuts down and restarts.

I cannot get to the desktop (it reboots as soon as I try to click on a user
and the word “Welcome� appears), I cannot start it safe mode (it reboots
before it gets there), I cannot start it with automatic restart on system
failure disabled– it just restarts so I do not see any bsods and error
numbers . I cannot believe that Microsoft designed this OS so that it cannot
be overlaid, (reinstalled over itself) without destroying users accounts and
programs the way that XP could

I have cleaned a number of virus from the system and check the drives
physical interity by scanning it with another computer. I have also found
(and removed) one stick of bad memory. I have tried working with the Windows
RE (Windows Recovery Environment) from the installation DVD. It runs through
its startup recovery, it reports that Startup Repair could not detect any
problems, yet when I the machine and then it reboots when it gets to whatever
that screen is called.

I can get to the Windows RE command prompt (not safe mode command prompt) if
I boot from the install DVD. I have tried to run SFC, eventmon, and eventvwr
from there but they don’t seem to work.

Can anyone help me?

Amgeek