I plan on building a desktop PC on which Video-creation and editing will be the main activity, together with photograph and general graphics manipulation and processing.
My preferred O/S is Win7 Ultimate SP1 64 bit.
I have no intention of continuing with Microsoft when support for Win7 is removed and will instead move to one of the Linux platforms. (Brand/Version not yet established.)
I understand there is a problem with compatibility of some Intel products (motherboards, processors etc.,) and Win 7.
I would appreciate any advice on choosing the Motherboard, Processor and Graphics card which would provide me with the best solution for the activities stated, and taking account of the O/S situation.
Intel is no longer in the Desktop Boards business, so you will have to look to third-parties for boards. Insofar as processors are concerned, you are definitely looking at a Core i7 class processor for video creation and manipulation.
All processors in the 7th gen. Kaby Lake and newer processor families are supported only on Windows 10. If you want to stick with Windows 7, then you will need to look at previous processor (and board) generations.
Hope this helps,