Repair Install Freezes At 72%?

My attempt to do a Repair Install of an Upgrade to Home Premium from Professional freezes at an indicated 72% completion of the Transferring Files, Settings, and Programs section. That figure is misleading because it actually stops at 99.9729+% with only 77 items left to transfer. I have ran the install program many times and each time it freezes at 77 items left. Even though the number of files to be transferred changes each time, the freeze occurs at 77 left to go. I have been looking through the forum and reading the sticky threads above searching for answers. One of the suggestions is to check the memory. So I downloaded IsoRecorder and Memtest86+ and burn to a CD. Boot the computer with the CD and don't get a screen with all the information as shown in the various Memtest86+ screen shots. After two hours of waiting it is apparent that this is not working. Maybe a bad download, maybe a bad burn? Oh, well. I next get an openSUSE distro disk that has a memory test on it. Again it is Memtest86+ and again the same incomplete screen. Memtest86+ does not like my laptop, processor, chip set or something. So I run the Windows 7 Memory Diagnostics test. First ran the standard test for 10 passes. No problems found. Then I ran the extended test for 10 passes and still no problems.

Then on my list to try before the next install attempt was to chkdsk and to defrag the HDD. The computer is set to do a defrag weekly but it has been a few days since the last one and you never know. Now to run the install and again it freezes with 77 to go. It is becoming tempting t wipe the HDD and make the laptop a dedicated Linux machine but I hate surrender. Some threads mention the possibility of problems reading the Windows 7 install disk and suggest copying it to another DVD or USB stick. Sounds like it may be worth a try. But before this can happen a friend offers the use of his install disk. I accepted and it worked. I now have Home Premium back on this computer. The nice, sparkly DVD I bought from Amazon for this project evidently has a bad bit on it from Microsoft that is corrupting a file and thus blocking the install. I don't know if copying the DVD to another media would of worked in this case but the suggestion triggered the acceptance of the possibility of a problem with the official DVD and the try with another Microsoft DVD that worked.