"Preparing To Configure Windows. Please Do Not Turn Off Your Computer"

The answer seems to have been found; but the above, sorry, was temporary.  It did stop the repeated efforts to update; but they started again.

The problem was likely caused by failure of a tiny piece of brittle plastic that was supposed to keep the LAN network cable stuck into the back of the computer! The plastic bit was no longer attached to the cable plug when the LAN connection, on the back of the computer, was checked. That computer's connection to the Internet was faulty; it even started to occasionally refuse to connect to the modem; so physical cable-type connections were checked and found to be the most likely cause of the problem

The connection to the Internet, after writing the above, ran into serious trouble; 50% packet loss doing a trace-route, for example; lots of waiting and/or failures-to-connect. Neither the laptop, by comparison, nor another computer Wi-Fi linked, had any problems at the time, with connecting to the Internet.

Replacing the cable fixed the packet-loss problems...and all other problems connecting that computer to the Internet. A cable almost breaking away, but still connecting (but not pressing contact-to-contact as much as it should) can/does cause intermittent connection problems, obviously.

Windows 7 has in the Control Panel, a log of updates installed.  Checking that showed that, for the last week or so, lots of updates failed; and, yes, they were tried again, repeatedly, during that time.  Occasionally an update did get through; but there was a perfect list of updates that were being attempted, again and again.

The Windows 7 non-stop update repeats (for every reboot and every shut-down), was different from XPPro successfully updating, every day, the same thing (same numbers every time). My XP update-repeat problem was anoying; probably based on a software problem; but the Windows 7 wasn't a Windows 7 problem (Windows 7 did a perfect job of keeping trying to connect and update).

After replacing the cable, and manually checking for updates, they got in quickly, without errors.

We had problems, for a while, connecting to the Internet using a 5 years old wireless modem on XP and Windows 7 but especially Windows 7 (ok for five years; very bad on Windows 7).  That was replaced by a new wireless N modem; no more problems connecting to the Internet by Wi-Fi (and it works through a couple more brick walls compared with the g modem). The shop said that the old modem would have been the cause of the Windows 7 Internet failures; and replacing cured the problems

Well, this WSIF (Windows Software Installation Feature)-related issue seems to be somewhat caused by third party drivers installed on the OS.

I've had installed Windows updates and hotfixes before installing any driver and I didn't have noticed this problem therefore. So if you want to install Windows MSU packages on a Win7-based 64bit machine which has 3rd party drivers installed, a reboot after each MSU installation (even if it's not necessary) is required to prevent the computer to hang during installation. This is a temporary solution until a WSIF hotfix for Win 7 x64 comes into surface.

AFAIK, Microsoft has released 5 patches for the Windows Software Installation Feature for Vista a couple of years ago. Perhaps the folks at M$ will launch a similar hotfix for Windows 7 which definitely eliminates these system hangs.

I'm having the same issue with my Sony Vaio VGN-NR160E. The notebook is in loop: "Preparing to configure Windows. Do not turn off your computer." This is going for at least 9 hours. I noticed on the posts here that it seems that I have to really wait a little bit more. I will try, but does not make sense. I did try F8 and all the options there (Safe Mode, Safe Mode with Networking...). I also tried to boot from the original Windows 7 CD and tried all the recovery options there. In summary all failed. I'm again stuck with the "Preparing to configure Windows..." This is my wife's notebook so I don't know how many updates were downloaded and are being installed, but it is very strange to stay in this loop forever... I tried all the solutions listed in this thread, in summary:

1. to wait for hours...some people said they waited from one day to the next....
2. to reboot in Safe Mode or other options after hitting F8.
3. to repair from the Windows 7 CD

All options failed and the notebook stays in the loop: boot, "preparing to configure....", reboot, "preparing to configure...".

I will try to copy my files and reinstall Windows... Thanks Microsoft.

yup! this is what i had to do exactly. Mine got stuck at "Preparing to configure ..." screen. But I just shut it down manually at that screen. It then loaded up. The "Preparing to configure ..." screen came again but only lasted a few seconds. It then went to Updating and is now done.

Fun fact: I was doing 70 updates!

I don't think waiting is the answer. I think it just gets stuck and a manual restart at the screen is necessary. It loads up fine after that. Btw, I have a sony vaio...intel core2duo processor and windows 7 hoe premium.

So glad i found this forum and answer.