Windows 10: An operating system was not found......

Your screenshot never made the post. As for the Rufus tool I never even tried that one while I have used others in the past. You might want to consider giving the free trial version of UltraISO a go and if you are looking to get the combination iso with both Home and Pro in both 32/64 flavors that would be the larger iso downloaded from the Windows download page not Tech Bench.

The Media Creation tool is what to use to grab the TH2 update where you only choose English not English International, Windows 10 not K or N unless you were upgrading the N or K edition of a previous version released for a different region of the globe. Don't forget MS has Windows going out to at least 192 countries and likely even more.

The MC Tool once downloaded is run by a right click and choosing the "run as administrator" option to insure the best results while nothing else is running as far as any large app in the background. Depending on the connection you have the download should only take about 10min. or so with cable internet and a little slower for dsl on average. We all know dial-up is a snail's pace there! Windows 10

The first thing you come to with the tool will be the language followed the option to either upgrade on the spot or save the 10 download where you choose the save to drive option. The next screen will be either to see the iso written to a flash drive where you will need either an 8gb or 16gb to cover the 5.48gb size of the combination iso which equals the 4 in 1 iso that was previously seen by downloading the four images from the Tech Bench site and then extracting both the 32bit and 64bit into the Pro(recommended) dual flavor 32bit and 64bit folders already written to the flash drive but are emptied out. That was for the 10240 July release there.

MS decided to roll everything in the Threshold 2 since it was going out to everyone running 10 and would automatically detect what you have on. When booting live however you have to make the manual selection for 32bit or 64bit first and then choose which edition during the first few screens of the fresh install. Since 10 was already activated you would simply choose the 64bit Pro options and call it a day since the fresh copy of 10 should be found activated already upon reaching the desktop for the first time and then once 10 finishes loading go into the Start>Settings>Update & security section to look in Activation to find you are all set or only would need to wait a day if for some reason the activation wasn't immediate without the need for any product key. You simply click on the skip option when that appears during the installation.

You won't have any need for seeing 7 Pro go on first eliminating that extra step as you would have back before the TH2 came out on November 11th. Here I have a laptop upgraded to 10 that will now either go into a shop to see if the back light went or if it will take a separate graphics card as nothing is seen on screen at all and was thought to be a failed drive but nothing. A new 10 laptop is now being priced. If there's nothing major like a failed chip on the board then the new larger hard drive will actually see a clean install of the 64bit 10 Home there that replaced the 32bit 7 Home Premium. The laptop as bought as a gift for someone now in a care facility back in May 2012 so it has some millage on it. A separate 64 Home 10586 1511 iso to burn to disk will be needed since you can't boot from anything usb since there isn't any option to even get into the bios setup on that one! The optical is already first in the boot order courtesy of HP! mainly for recovery media HP didn't provide but you would have to see made up.

If your situation however once the flash drive made up either with a Tech Bench download for the separate 64bit flavored Pro iso or downloaded by the MC tool you can try the UltraISO app that so far has been in use now for 6yrs. already first for 7 and later for usb install keys for the 8 Customer Preview. It also works quite well for seeing live Linux sticks made up and you shouldn't have any problem using the trial version for seeing the 10 media made up.

 

You don't use rufus to create a bootable USB disk with just the ISO file copied to it. You download the ISO file to your hard drive and use RUFUS to create a bootable USB disk from the image contained in ISO file.

The absolute easiest and most foolproof way to make a Windows 10 install USB thumb drive is option one and let the media creation tool do all the work for you:
USB Flash Drive - Create to Install Windows 10 - Windows 10 Forums

Option two is how to use RUFUS. When you select "Create a bootable disk using ISO image", the ISO image must be stored somewhere other than on the USB drive you are attempting to make bootable.

 

I would do both here of seeing the 10 iso written immediately to either the 8gb or 16gb flash drive as well as downloading to save the iso for later use if not simply to keep onhand. Unfortunately at present you first need to get 10 running which will require seeing the 10 media made up.

The problem with the Rufus or even when trying the UltraISO program's free trial for the media you need a running OS in order to see that happen. The same for the Media Creation tool there while that won't require any installation on the machine you download 10 to. You can have a temp folder on any Windows machine for initially seeing the 10 media created and later once 10 is up and the extra drives are plugged back in you then download to save the TH2 iso to.

Now if the OS drive itself hasn't failed you should be able to boot live and put the clean install on and still see the folders outside of the Program Files, Program Files(x86), and users folders intact in what ever other folders you had on the drive besides finding a new Windows.old folder.