Just changed my feeble mind. Going for it like a skateboarder on the stair handrail of the Buckingham Palace.
Have been conversing with several first adapters on the Computer World comments section. Did I mention I really hate Windows 8.1? Did I mention it more than a dozen times? Lately?
1. Desktop with Win 8.1 From the response, I think that on the weekend of August 1, I will do this and take the precautions for external disk backup and the Undo. The PC came with Windows 8.0 installed (HP Envy). A little worried since in the past, full installs work better than an Upgrade.
2. The kid called from NYC, NY. He got a 2 month gig on a ship and expects to come home the beginning of September. His 3 year old HP 17" Portable is going though blue screen Disk Scan on every startup. It survived 300 days at sea and his academy homework. It runs Windows 7. I can replace the Hard Drive with a SSD Kingston for about $100 USD. Fresh hard drive, might as well go for Windows 10.
3. Two early adopters that had Windows 7 were seasoned people. They were never able to get the network working. MS offered no real help. MS also forgets to mention setting ROM BIOS to some USB boot settings BEFORE installing Windows 10, or it can't undo.
A. The Windows 7 Ultimate with dual SSD and 2x 30" advanced graphics desktop will not be touched.
B. My HP Envy 3D Portable with dual SCADA drives, 1080 monitor (120 hz) and i7 first generation will be upgraded. This portable runs so high at our altitude (5,280 feet) it melts the varnish on a wood table, burns legs through a pair of jeans. HP never fixed it. The extra large battery only last 11 minutes. I am going to replace the Dual SCADA with a single SSD and see if that changes anything. As of now, it is only used a couple times a year for Power Point.
I will be back in August to with an update.