Noticed midmorning that my windows 7 computer was busy downloading a windows update.

I took a look at it was 27% of the way downloading approx 2.7GB of windows 10.
It completed and it was time to start the upgrade.
at 12:10 the system restarted and the install began
at 12:47 it restarted, 30% complete
at 13:13 it restarted, 75% complete
at 13:25 it restarted and I logged in
at 13:33 the desktop appeared, but with only 1 display at a low resolution
another restart and it found the nvidia geforce GT430 drivers, card and 2 displays and set them to the correct 1680×1050 pixel resolution.
Overall about 1.5-2 hours after download and it was complete.
Over the next 20-30 minutes or so it was slow to respond. mouse movements, clicks, etc were all slow. Disk I/O was 100%
Now, 1 hour after, CPU use is low, about 10%, memory use is 2.5GB (or 63% of the 4GB onboard), Disk use is now much lower 0-10%

A quick test of must have programs showed all to work: thunderbird, stellarium, ms office 2013 (after 5 minutes of reconfiguration), adobe reader, firefox, chrome and more. So far so good.
Keyboard and mouse responsiveness are also better now. Pretty much the same as before with Win7.