Thanks for all the help on this site! Was able to upgrade from Windows 7 Pro to Win10 Pro (Activated) without any major problems. Had to force the Windows 10 upgrade via Windows Update deleting all files in the "C:\Windows\SoftwareDistribution\Download" folder, then use the "wuauclt.exe /updatenow" from an admin command prompt (details of this process on multiple threads/sites). Upgrade finished in approx 45-60 minutes with all devices working in Device Manager on an older Asus p8p67/2600K system. After upgrading ran into only 1 snag when using the Media Creation Tool in Windows 10 to create the ISO/DVD in order to perform a clean install later. Ultimately it appears IMGBurn was hanging the system and was unable to create the DVD so removed IMGBurn and used the Win10 built-in IMG CD/DVD burning tool via Windows Explorer without a hitch. Now all apps and devices I have are 100% working. With confidence I will proceed with clean install over the next 1-2 weeks. I have made a backup copy of all my drivers using DriveMax in preparation of the clean install but it appears Windows 8.1 drivers will work on 10. Thanks again, this site gave me all the confidence needed to force the upgrade.