Yeah, to dual boot Windows 10 and something else Secure Boot needs to be off. UEFI can probably be on or off, but I think it's easier to have it on.
I ended up reading various guides which talked about having to copy boot sectors and all sorts, but thankfully I didn't need to do any of that. It was actually fairly trivial once I thought about it properly.
Have only the empty SSD plugged in so the OS setups can't see any other OSes and get confused
Disable Legacy Boot in BIOS (or definitely don't pick it)
Run Win10 setup from USB media - making sure to pick UEFI boot option
Partition drive in Win10 setup - I split it in half, let Win10 install on the first partition - it split that into boot and reserved bits itself as usual.
Install Win10 - check it works
Run Ubuntu (or whatever) setup from USB - UEFI boot
Hopefully that sees you have a Windows installation and uses the extra unused unformatted partition
Install 2nd OS
Ubuntu 17.10 will sort the dual boot bootloader for you
Reboot and pick Ubuntu or Windows Bootloader from the Grub screen
It currently has a 10s wait on boot, might reduce it since 10s feels like an age!
OK, good to know... 18.04 LTS is going to be released in a few weeks (I've come to prefer the LTS versions because lazy). I installed a daily server build to an old work pc couple of weeks ago, bunged xfce and vnc on it, and it was one of the slicker Linux installs I've run in quite a while. Hit a couple of minor issues since, which may (probably) were unrelated to pre-release build. Got one (setting MySQL root login) fixed, and hoping the other, which is real legacy stuff (netatalk) will automagically sort itself out one day RSN.
“Exorcists are back – and people are getting hurt”
I usually do as well but I've found a few things I've wanted to use that weren't available or supported on 16.04. I've also had the issue of using a none LTS build and forgetting the lifespan is now very short.
My server is still running 14.04 LTS. I'll probably consider upgrading that to 18.04 after the first point update.
Yeah, I'd find 10s a bit long. I currently dual-boot Windows 7 and Windows 10 on my PC (Win7 being the default). I have it set to 3s, which I find to be a nice trade-off between giving me sufficient time to switch OS on those very rare occasions I boot into Windows 10, and not slowing down the boot process too much.
Would be good if computers had physical boot configuration switches, so you could just flick it to setting A or B when turning on, and remove the need to have any startup delay.
Got my other 18.04 issue (netatalk) solved by following compile/make/install instructions for 16.10 (apparently 16.04 is too old, go figure). Yay me. :-O~~~
We're watching the "directors cut extended version", which has discarded scenes restored from assorted damaged/unfinished takes. A bit jarring but the story has continuity.
“Reptilians Rule the World, Moon Landing Was Fake”
SSD prices have been crashing over the last few weeks, you should absolutely get one as your main system drive. There is no other upgrade comparable to the speed increase you'll get with an SSD.