M51ac can't do system recovery..........

[TheBiz]

I installed Windows 10 shortly after it was passed by Microsoft. It worked for about a year. Then Some file evidently became corrupted. I did a recovery whih worked fine and I got back to Windows 8.1. I stayed with Windows 8.1 for around 2 years. I installed many programs and all was well. I wanted to install a program for my wireless doorbell bit the program is only available for Windows 10. So, I tried to re-install Windows 10. It failed. I tried a search on the error code. I found several solutions. I tried every solution and none worked. Always reverted back to Windows 8.1. So, I backed up all settings and moved all important files to an external drive. I decided a full system restore would make it to where I could upgrade to Windows 10. The restore failed. I got a message 'Could not find the recovery environment'. I tried to make a backup recovery disc. No go. I Now regret not making a backup restore disc. I need a restore disc. Asus does not sell them. I do not really want to spend 50 bucks for one. Any help as to what I might do to get a restoral Disc? Any help would be greatly appreciated.