The way I see it now, is that you have exhausted everything that I could possibly suggest and you only have a couple possible options remaining to return your computer to a functional state, neither of which is particularly optimal.
The first thing I would recommend, if you have any personal data (files like pictures, music, documents, email etc.,) you need to take some preliminary steps to secure that data.
In order to do that you will need a second (working) computer, on which you can create, bootable media that you can use on your non-operational computer to boot that computer and either perform a disk image or simply copy off that data to an external resource such as a USB external hard disk.
Personally my first choice would be to download the free trial of Acronis True Image and install it on a second functioning computer and use that software to create the "Rescue Media" to boot your problem computer and create a Disk Image of the entire hard disk of your problem computer.
http://www.acronis.com/en-us/personal/computer-backup/
There are any number of other software options out there that will allow you to do something similar......
I just prefer and have used Acronis for years and have found it to be reliable and relatively easy to use.
As a second choice you could, again, use a second computer and obtain a Linux Distro Live CD ISO
My personal favorite
http://www.linuxmint.com/edition.php?id=191
OR
Some people prefer
http://www.ubuntu.com/download/desktop (choose your flavor.... Pick 32 bit if you are not sure).
I find Mint MATE a little easier for Windows Users to use.
Once you have the ISO you can use something like ImgBurn to burn it to a DVD or Rufus to burn it to a USB ThumbDrive to boot your computer with
http://www.imgburn.com/index.php?act=download
http://rufus.akeo.ie/
When you boot into which ever version of Linux you decide to use, you can use that to copy off your file to an external USB hard disk. Usually your C:\Users\YourUserName (that's your profile folder) if you have more than one user(s) you may want to grab any additional profile folders contained in C:\Users.
Those folders will usually contain most if not all of your critical data, unless you have moved them intentionally to another location, or created a non-standard data structure of your own.
In your case, you may also want to grab
C:\Windows.OLD (if it still exists) as this may contain files and folders from your previous Operating System, that you upgraded from.
After you have secured your critical data I believe you have three choices at your disposal.
1. Use your Computer Manufacturer's recovery partition to return your computer to its' former factory state, if that is an option.
2. Use the install media from your Original Operating System to reinstall the OS which you had previously been using
OR
3. And this will only work if your previous installation of Windows 10 had been running long enough to effectively been "Activated" on that machine.
Obtain (if you don't already have it) the Windows 10 ISO from either of these two resources.....
http://www.microsoft.com/en-us/software-download/techbench
http://www.microsoft.com/en-us/software-download/windows10
And perform a custom clean install of Windows 10
WARNING: All three of these potential options will assure that all your previous data and programs will be gone, so it is imperative that you make every effort possible to secure your important files in advance and confirm that you have them safe and that they are actually available to you from your external drive.