2) Seeing the size and number of partitions on that disk and how it's reported in Disk Management, I can tell that it is an MBR structured disk as opposed to a GPT structured disk. Being one or the other can impact your choices for change.
Or, using just MiniTool Partition Wizard you can certainly shrink the E: drive partition to only the size required, and add the free space to C: drive.
You can also, in Disk Management, remove the E: drive letter from the partition, but leave the partition there without a drive letter.
When I normally do my monthly image backup, Acronis always does a backup of "C" and "E" so I don't really want to hide the drive.
I might have to live with it.
Is it possible to delete it, then boot from a Windows 10 disk and recover the boot file?
You might want to install EasyBCD and see where your computer is booting from.
My guess is that when you did a clean install of Windows 10 it created it's own boot files on drive C:\ and is ignoring the files on drive E:\.
If EasyBCD shows a second option, i.e. drive E:\ you can remove the option there as long as it shows one for C:\.
If there are 2 boot options then it can be important to remove the 2nd option before removing the drive.
EasyBCD - NeoSmart Technologies
Get the free one at the bottom of the page.
Well I wiped drive "E" and my computer wouldn't start up.
Gave an error NTLDR is missing!!!!
I then booted from my Acronis disk, recovered "E" partition from an image and, phew!, it started up again.
Did a search using "Search Everything" and it came up with these files, not sure if it means anything:
I have since deleted the Insider build partition and have done a clean Windows 10 install to the empty space. When I did that, it created the 350mb system reserved partition again for the boot files, despite the fact that they were already on the first operating system partition.
Now, create a Macrium Reflect Rescue DVD/USB. Delete the E: drive partition again. Boot to the Macrium Reflect Rescue DVD/USB and use the Startup repair utility. See what you end up with. I think it asks you where you want to put the boot files when they are created and you would point it to your big system partition.
Created a Macrium Reflect Rescue disk, deleted the E partition again, put the boot files in C as per the instructions, but it didn't work.
My computer was stuck on the boot up. Managed to recover everything using Acronis again.
I am going to leave it as it is!
It is very stressful not knowing if your computer will start or not, I need a drink!
Thanks for your help Guys!