I have spent a number of hours troubleshooting the installation of Windows Vista Service Pack 1 on a particular Dell Optiplex 755, but I finally succeeded.
Symptoms: The SP1 update was downloaded and queued for installation via the Automatic Updates engine. When initiated, the install would look like it had completed (going to 100% through the third configuration step). But upon reboot, the installation would rollback all changes.
Troubleshooting: I did some of the normal troubleshooting steps, including downloading the full installer, disabling AV, etc. Each attempt to install the service pack was time consuming, but ended the same way. Eventually, I tried running the system file checker,but that didn’t change anything.
SP1 installation support: Microsoft offers free support for SP1 installation, so I decided to give that a try. The first suggestion was that I try the installation in a clean boot environment, created using MSCONFIG:
- Click "Start", type: MSCONFIG in the search box and press Enter.
Note: Please click "Continue" if the "User Account Control" window pops up. - Click "Services", check the "Hide All Microsoft Services" box and click "Disable All" (if it is not gray).
- Click "Startup", click "Disable All", click "OK" and restart your computer.
I made the changes and attempted the install again, but without success. I bundled up some log info and sent it off to my support technician. Her next request was that I repair Vista, using installation media of the same Vista version that was currently running on the system, by running setup and selecting the upgrade option.
I ran into some issues with unreadable media and had to perform a firmware update on my DVD drive, but I got that working. The upgrade/repair took hours on a relatively powerful system. It did complete, however, and then I was able to run the SP1 install from the version I had downloaded.
Since this was a very significant system update, it would be prudent to back up any important data before performing this procedure on any system. All my software and data appears to have been preserved, but this is a lightly used system, and my important data is on my network account.
