The Scroll 51951 was released in January 2011 and the basic specifications of tablets are now light years ahead of what they were in 2011.
If you are able to enter recovery mode then you might try a factory reset or try the update again using
this file that you will need to put on a micro SD card so your tablet can read it. I don't know how to do this on your particular model so I hope you still have the instruction booklet.
Your thinking about android based on your Windows experience is not quite correct, but I will continue the analogy to hopefully be of some help to you.
As you say, Windows is an operating system which you need to install first of all - before you can install your programs or applications which depend on the operating system to run.
Android is just the same but we refer to it as firmware, I suspect because it also contains the instructions to allow the device hardware to be recognised and therefore function. To be honest, I don't actually know the original reason for this but it makes sense when you consider that a desktop PC usually has all its
Basic
Input
Output
System built in, i.e. the BIOS chip, which controls the main-board functions independently of an OS. Things like memory management, USB or PS2 connectivity, CPU settings etc and if you wish to update (flash) your BIOS on a desktop PC the data we flash is called firmware because it is independent of and not reliant on an operating system for its basic functioning.
As an experienced Windows user you will no doubt understand the risks involved in flashing the BIOS of your PC, how important it is to ensure you have the correct fully compatible BIOS update which you need to match your particular hardware.
You also no doubt have heard how easy it is to effectively destroy a PC by getting things wrong and flashing the wrong BIOS image or having a power interruption during the process. In such instances, unless you can physically replace the BIOS chip with a working version - your PC is effectively bricked and useless.
Unfortunately, with your tablet when you get it wrong you haven't got the option of physically replacing a BIOS chip as all the necessary information for the initial communication with an OS is included in the android image (firmware) update - not on a separate BIOS chip. Therefore, if you happen to flash the wrong/incompatible firmware to your tablet you can end up with a permanently bricked device.
The first android powered mobile phone was sold in October 2008 and android has continually developed since this time using Software Development Kits SDK's and the current popular version is 4.2.2 - JellyBean. The development of android, just like Windows OS's are not always backwardly compatible so sometimes there is no benefit in getting the latest assuming it will be the best. You can read a lot about android history and development
hereSometimes the terms SDK and API are incorrectly used when relating to android software development. SDK is the
"Software development kit" which has its own versions and updates and the API refers to the
"Application Programming Interface"Version history by API levelThe following tables show the release dates and key features of all Android OS updates to date, listed chronologically by their official application programming interface (API) levels.
Android 1.0 (API level 1) 23 September 2008
Android 1.1 (API level 2) 9 February 2009
Android 1.5 Cupcake (API level 3) 27 April 2009
Android 1.6 Donut (API level 4) 15 September 2009
Android 2.0 Eclair (API level 5) 26 October 2009
Android 2.0.1 Eclair (API level 6) 3 December 2009
Android 2.1 Eclair (API level 7) 12 January 2010
Android 2.2–2.2.3 Froyo (API level 8) 20 May 2010
Android 2.3–2.3.2 Gingerbread (API level 9) 6 December 2010
Android 2.3.3–2.3.7 Gingerbread (API level 10) 9 February 2011
Android 3.0 Honeycomb (API level 11) 22 February 2011
Android 3.1 Honeycomb (API level 12) 10 May 2011
Android 3.2 Honeycomb (API level 13) 15 July 2011
Android 4.0–4.0.2 Ice Cream Sandwich (API level 14) 19 October 2011
Android 4.0.3–4.0.4 Ice Cream Sandwich (API level 15) 16 December 2011 (last version to support Adobe Flash Player)
Android 4.1 Jelly Bean (API level 16) 9 July 2012
Android 4.2 Jelly Bean (API level 17) 13 November 2012
Android 4.3 Jelly Bean (API level 18) 24 July 2013
Google released Jelly Bean 4.3 under the slogan "An even sweeter Jelly Bean" on 24 July 2013 during an event in San Francisco called "Breakfast with Sundar Pichai". Most Nexus devices received the update within a week, although the 2nd generation Nexus 7 tablet was the first device to officially ship with it. A minor bugfixing update was released on 22 August 2013.
Your Tablet originally shipped with firmware Android 2.1 Eclair (API level 7) which included a specific set of libraries or code the tablet needed to allow it to function. If you can still communicate with your tablet via USB and a PC then it may be possible to salvage your tablet - but this is something beyond my skills but you may learn how to by reading more.
APIs (application programming interfaces) are the sets of instructions (code words) that instruct an application how to build and run itself. It's an extended "library" of commands added into an existing programming language. An Android API library is a set of Java commands built specifically for Android. A special set of Java commands specific to each API version.
If you learn about
ADB Android
Debug
Bridge (adb) is a versatile command line tool that lets you communicate with a connected Android-powered device so you can issue commands and edit/change the firmware or instruction files. As a Windows user you will realise that this is no easy task. I can only suggest, if you want to learn more then start
hereGood luck and be sure to come back and tell us how you get on.