I just upgraded to W10 a few days ago. All good. I will stick to W10.
What I have done BEFORE the Upgrade: Moved all steamgames to my second HD. Copied my documents-folder to the sec. one.
Installed W10. Than went to System Retore and wiped out my main HD, W10 puts a clean fresh install on that.
Then I installed Steam. DL direction in the settings to my sec. HD
Steam found all my games and only reinstalled a few files for each game.
Pasted my Doc-Folder back to the main Hd.
Now I have a clean install with all my games. Happy with that.
Remember:
Save ALL the content you would use like Text, pdf, personal files etc to a sec HD before you upgrade.
Cheers
Andrew
PS:
Windows 10 Games Compatibility List
http://answers.microsoft.com/en-us/...t/a31335a8-730f-4ac9-8c19-7c8c3a664ced?auth=1
If you want to play a game on W10, that was running fine on older system, you will have no problem with that. If any problem show up on W10, all you have to do, is click right mouse on the game, select "Run this program in compatibility mode" and choose your old system...