Well, UAC and my admin acct also disappeared - a trip to Youtube   unearthed a decent video:[URL] - possibly self inflicted ! which helped fix that - phew! Can't live without an admin account . Also got new desktop themes which could be used with a minor registry hack. I still want to complete activation - I have all the proof that I am the registered owner of the copy of Windows 10 Pro and have the 25 digit code, but MS seems to make everything harder than it should be ! Thanks again for all the help.
Are all XPS 8940 motherboards (Intel CPU) alike? Mine just decided to die, after overt a year of intermittent crashes started by just a tiny bump or shake of the box  - I put up with this for over a year- just did a hard shutdown and restart - and continued on until on start led in start button and green led in power supply each on for a second or two then stop. Was advised that this is a classic bad motherboard  symptom. I have upgraded the CPU cooler, case fan, 500Wpower supply, voltage reg.heat sink ( done after the crash in a futile trial and error w. steep learning curve) , has 10th Gen I-7, 64GB DDR4, two 2TB HDD, and much other. I thought I might buy a bottom of the line XPS8940 and swap components into it over time. I've never had trouble adding or swapping components, but replacing a mother board is a bit scary to me. Suggestions ?
XPS 8940, motherboards alike?