I resolved my issue of not being able to boot in Safe Mode. A normal full boot was never a problem, only Safe Mode boot. Many threads on the net point to a corrupt file namely Classpnp.sys as the culprit. I'm guessing many people believe this as the BSOD occurs immediately after the loading of this system file. I don't believe Classpnp.sys is the issue but simply a co-incidence because this .sys file is actually the last driver
/system file to load before the Safe Mode boot process continues to the next boot stage, ie. BSOD caused by some safe mode boot up action after Classpnp.sys has successfully loaded.
I gave up on a quick resolution of the problem & decided to carry out a full re-install of my Windows OS. After re-installing the OS successfully I then went about finding what Windows update, program installation, etc. caused the re-occurance of the Safe Mode BSOD. I installed a couple of programs at a time then re-booted trying Safe Mode. The same thing with the Windows updates. Eventually I found the culprit - EASEUS TO DO BACKUP VERSION 5
So, if you have this program installed try uninstalling it to see if your Safe Mode BSOD dissapears.
Hope this solution works for others. If I recieve positive responses I'll write to Easeus to inform them that their V5 is corrupt (& perhaps tell them hat I think
Best of luck!