Hello, After 2 months, I finally got 8.1 to upgrade correctly. What I had to do what resize my primary partition. The partition was only 100mb and 93% full. I was very scared to try and do this but was so frustrated at MS doing nothing to help that I tried it. It was all or nothing. If this did not, I was going to ban all MS products for life. What is amazing is that MS does not have a partition program that resizes a partition for what is needed to do this. Seriously MS? At first I tried EaseUS Partition Master 9.3.0 and had no luck. I created a new partition, but not one that was "next" to the primary partition, so it would not work. I then downloaded MiniTool Partition Wizard. What was great about this program is that it does everything for you. I just said I needed the resize the "Active & Boot primary partition" from 100mb to 400mb and it did it all on it's own. It "took" the 300mb from the main "System" partition and automatically added it to the "Active and Boot primary partition". The "Active and Boot" primary partition is the one you need to make 400.00Mb. I went from 100MB to 400 Mb and the upgrade finally took without incident.
I now have used 298.11Mb of the Active and Boot Primary Partition with 101.89Mb free. Both file systems are NTFS. After you choose to "Move/Resize Partition" my computer said it could not complete the request until it rebooted. I selected "ok" and the computed rebooted and "MiniTool Partition Wizard" booted up and started the process. Please note it took almost 2 hours to complete the process. I did nothing else. I came back and it then booted right to Windows 8.1.
In conclusion, it was clear that the "Active and Boot Primary Partition" did not have enough free space on it to complete the upgrade. It was not, as MS suggested and I knew, that my computer was not compatible with 8.1. That was insulting for MS to suggest. How can a company worth BILLIONS of dollars not make sure that as part of the installation process, that a used has enough free space available to install the upgrade? How can they cannot come up with a simple process that checks a users computer BEFORE beginning the process? Then of course it would require MS to come up with a simple solution.
Anyway, I hope this helps someone stuck in the same jam I was.
MiniTool Partion Wizard Home Edition was the answer. v.8.1.1 I admit to being very scared to try this as I read some had issues trying this. I can only share what I did and what worked. I did run Malware Bytes and CC Cleaner many times before to make sure there were no issues before trying this solution.