When I refer to mounting the downloaded ISO files and 'virtually' mounting them, I'm referring to using a utility like this:
http://www.slysoft.com/en/virtual-clonedrive.html
(Click to download, from the next page pick 'Virtual CloneDrive' at the bottom of the list - this is Freeware, and download).
This is the one that Easy Supply incidentally - it is free and does the job. Basically, an ISO is a compete imaging of the contents of a CD / DVD-ROM Disk. Once you make an 'image' of the Disk it is saved commonly as an ISO file. These are often used for making an exact digital copy of a Disk that you can archive off in case your original becomes damaged. Using the Clone Drive utility above, you can 'mount' the ISO image file. The PC will assign a new drive letter to the image. When you browse the new drive, it will be like you are using a real DVD-ROM drive, only you aren't.
Installing DocBackup / SEDRE from ISO Images Guide
1) Download VirtualClone
2) Browse to the folder where you have saved the downloaded DVD1, DVD2 & DVD3.ISO files.
3) Right Click on DVD1.ISO and choose Mount (Virtual CloneDrive E:) - Note it may say F: or G: etc., - depending on each person's PC.
4) Now you can open 'My Computer', and you will see whatever the new Drive letter that was assigned listed. Right click and choose 'Open'. Note: If you have 'Autoplay' enabled, it may well open up the drive letter for you - in which case just choose 'open folder to view files'.
5) From there you can run the setup programme.
6) When it wants Disk 2, go back to 'My Computer' and right-click on the BD-ROM Drive (E:) DVD1 (in my example) and you will see an option VCD (F:\DVD1\DVD1.ISO) or similar. Expand this, and you will see the option to 'Unmount' - select this.
7) Wait for a second and it will unmount the drive.
8) Now browse to DVD2.ISO and follow the same procedure as above to 'mount' this drive. Only this time - you don't need to go into the folder to run anything as the ServiceDoc is still waiting for Disk 2 - so when it has mounted, switch back to the dialogue box asking for Disk2 and click OK.
9) DocBackup will continue installing.
10) When it asks for Disk3, do the same process as above.
Sorry this is a bit long-winded but I'm trying to make it as simple as I can - It seems I'm failing miserably though!