MS forced install to Windows 8.1 after I click on Remind me later.

The mystery volume is likely the MSR partition.  It doesn't need to be defragged, nor does any drive that is showing only 4% fragmentation.   Defragging is a highly overrated operation for most systems anyway.  

As far as reverting to Windows 8 is concerned, you can do it but there's apparently no guarantee that a forced update won't happen again.   There have been many reports of systems being updated without the consent of the owner, but there is nothing from Microsoft on this subject as far as I know.

NEW DRIVE CREATED BY WINDOWS 8.1 UPDATE

After I was FORCED to update from W8 to W8.1, a strange, "mysterious drive" appeared with no letter when I tried to defrag/optimize my hard drive. This drive is fragmented by 4% and cannot be optimized. In addition, I have two additional partitions, for a total of five. When I had W8 I only had three partitions, and ALL of my hard  drive could be optimized.  Now, I have this unknown drive which cannot be optimized.

Others have also been confronted by unknown drives appearing in disk management after having updated to 8.1. Here is a link about the dilemma.

https://social.technet.microsoft.com/Forums/windows/en-US/40f23611-658c-47e8-abe4-ca2843d30228/strange-new-drive-created-by-windows-81-update

Ironically, for me, it is W8.1 which is not supported as it has delivered a drive which is identified like this: \?\VolumeI had no major problems maintaining my notebook with W8. Now, I have a 4% fragmented unknown drive. This sickens me. As well, additional space on my hard drive is now being occupied by the recovery drive for W8.1. I now have two recovery drives: W8 AND W8.1

I want to do a system recovery and remove windows 8.1. But first, I would like to know if it is possible to remove any future threat of being forced to update once again. And, I still want to know why this forced update happened. Please, would a Windows Expert respond? Tell me why this happened. And, can I prevent it from happening again. (Don't tell me how to live with W8.1, or how this forced update is ultimately good for me). I purchased W8. And, I want W8.****

Windows 8.1 was released October 17, 2013.   Support for Windows 8 is supposed to last until 24 months after the general availability of WIndows 8.1 according to this link:

http://support2.microsoft.com/lifecycle/search/default.aspx?alpha=Windows+8

By my calculation that means I am supposed to be able to use Windows 8 and be supported until at least Oct 17, 2015.

As far as I'm aware updates will be released for Windows 8 up until January 2016. In my mind this gives me enough time to install Windows 8.1 when it is convenient for me and only after I have taken any steps necessary to avoid problems after the upgrade. Or at least it would be if Microsoft stopped trying to force the upgrade upon me.

Just a word of warning to people who don't want this forced upgrade. Today I got a new update come through, KB3008273, which replaces KB2973544. From what I understand these two updates allow Windows 8.1 to be automatically installed if you already have KB2871389.

Windows 8.1 was released October 17, 2013.   Support for Windows 8 is supposed to last until 24 months after the general availability of WIndows 8.1 according to this link:

http://support2.microsoft.com/lifecycle/search/default.aspx?alpha=Windows+8

By my calculation that means I am supposed to be able to use Windows 8 and be supported until at least Oct 17, 2015.

**"**Windows 8 is unsupported and should no longer be used."

Excuse me...since when!!!

And even if that was the case, which I do not believe, it doesn't give MS the right to install a new operating system without my CONSENT!