Aura,,Problem Solved!!!
The Repair Install you suggested above did not work either. I had the usual problem as before. i.e. halfway through the installation I would get a message that the update to SP1 failed. As a last resort I booted the computer with the DVD and during the installation I chose to format the HD with the reasoning that any corrupted file or registry that may be stopping the installation will be wiped out and I will do a clean install. Half way through the "files expansion" phase I got an error message saying that the installation could not be done due to an unknown reason. Now I was really stumped. You and I had cleaned up the file system to work flawlessly, the HD was reformatted and I was still unable to either update the Win-7 to a SP1 or do an clean install from a DVD
Then I read in one of the other forums a comment that if the SP1 installation consistently fails then the problem COULD be due to the RAM and motherboard interaction. Particularly if the mobo is 6 or 7 years old. The suggested possible approach was to reduce the RAM capacity, install the OS and then bring the RAM up to the original capacity after everything is running. So I did that. I reduced the RAM from 4GB to 2 GB and the installation sailed through flawlessly. I've brought the RAM up to its original 4GB and am now in the process of adding my applications. My data is on a separate partition and also backed up, so I'm OK there. My mobo is an ASUS P5N E-SLI and has their latest BIOS driver
I am not knowledgeable enough to understand the mechanism of how the RAM and the mobo interact. Maybe somebody at this forum may have an explanation as to why less RAM interacts flawlessly during installation of an OS whereas the higher capacity RAM would hang up, and yet with the higher RAM capacity the OS runs fine and faster during normal operations and other updates.
Anyway Aura, I very much appreciate you sticking with this issue and being very patient in attempting to solve this problem which turned out to have an unexpected solution. Thanks again