So my Dell laptop most recently had 2 bootable drives: the original WD Blue spinning rust and a sandisk M-SATA card. Both were running W10 a month ago.
Reverting the spinning rust drive to W8.1 without removing the M-SATA drive borked that drive, probably damaging the boot manager and making it unable to boot the machine. Fine, I was planning to wipe & reinstall W8.1 from my Dell recovery USB stick, except that the drive had software on it that I wanted to deactivate in order to activate it on the fresh install I'd planned to create.
So out with the spinning rust drive in my morning coffee break.
The USB drive (another) I'd used to install W10 on it originally couldn't repair the drive.
As a last resort I popped in the Dell recovery drive and, within a few seconds the repair was done & drive bootable again. Excellent.
Photos 10 > deactivate > done.
Suddenly notice the trackpad works.
Really well (i.e. better than under W8.1).
After every reboot (which only takes a few seconds, thanks to using SSD, instead of about a minute using spinning rust).
After >30min of firefox usage at lunchtime I've not seen the graphics driver crash once.
So now I have a dilemma. Simply pop the spinning rust back in, close up the case and enjoy my better functioning W10, or continue with plan A and install W8.1, with all the delays, updates, software reinstallation and copying across of files (I'll have to move the lightroom catalogue back again regardless) required.
It's almost 5pm. Think I'll wack spinning rust* back in and see how we get on for the evening. W10 IS nicer to look at than W8.1, although the latter is warmer & friendlier in some ways (and I have more control over updates etc).
I could never have this kind of dilemma if I'd stayed with Apple. ;-)
*Amazon had a Sandisk 1TB SSD for £142.95 over Christmas, but I just couldn't justify the outlay, even for such a bargain.