To repeat: I have a Toshiba C55a Saltellite Laptop computer purchased two years ago on which I uploaded Windows 10 free edition as a trial expecting it to work without flaws since had been available and in use for some time. It worked well for about three months until an automatic upgrade caused the system to crash.. Now it turns on and tries to load the Toshiba software and give me a system error "unbootable boot volume' tries to restart itself and fix error but get stuck on a blank blue screen. It will not recognize the restore partition when I attempt the F12 HDD restore method. Ends up back at the blue screen.. Do not have a restart disk. How can I fix this problem?
The hard drive may be faulty rather than a Windows update causing the problem.
If that's the case, and you didn't make a set of factory recovery discs which all Toshiba laptops enable you to make, then you're in a fix.
Test the hard drive confirm drive failure. If it's failed, order a set of recovery discs here (European models only: https/backupmedia.toshiba.eu/).