Thursday June 2, 2016 I upgraded to Windows 10.
The only problems I encountered were photo viewer and Firefox freezing while running flash videos. These were simple to fix. By default the photo viewer is configured for Microsoft account photo viewer. Under settings, system, Default apps I simply changed the Photo viewer to Windows Photo Viewer. Firefox required disabling hardware acceleration in flash. Right click on any video display and choose Settings to uncheck Enable hardware acceleration.
Since I was using 32 bit Windows 7 Professional Microsoft installed Windows 10 Pro Version 1511 build 10586.318 32 bit.