Due to potential bugs, I helped a client to boot Windows 7 on an Optiplex 9010 that was originally set for Windows 8 from the factory. This was an easy procedure for them to follow but as time came to boot Windows 8 once more on the Optiplex 9010, the client kept getting the message saying that no boot devices were found.
After a little investigation for the client, I discovered that the Windows Boot Manager was removed accidentally by the client’s inhouse technicians instead of being unchecked (which prevented the EUFI mode from working correctly) on a few of their Optiplex 9010. If this should happen to you, here is a configuration from one working machine that you can code into yours. I manually added the information into the BIOS settings since I could not cop and paste.
Boot Option Name:
Windows Boot Manager
File System List:
So, did this tip work for you? You can contact me to let me know if it did or not.