I upgraded from win7 64bit to win10 two weeks ago. Did not do a clean install, used the keep all files, folders and programs option. Process ran very smooth. Did have to re-install some software drivers when it was done. You will know which ones when a device you have installed is not working. Just re-install its driver. An example was G510 gaming keyboard. Keyboard worked but my programed quick keys did not. Driver re-install fixed the problem. Other problem was with Firefox. Had to research on how to make it my default web browser thru win10. Another easy fix after I researched via the web. Also windows media player will no longer play CD's with win10. Changed that with win 8.1 don't know why. The program is there but you will have to get a third party video player. Plenty to choose from I use VLC to play by cd and dvd movies.
Forgot one last thing. Had to re-do all my GForce video card settings after win10 install they went back to default and my monitor screen was a little dark. Another easy fix. Must say my graphics are a lot more vivid with win10 than they were with win7. Also the ZOS launcher news feed that did not work with win7 after it's Feb 25th update worked again after installing win10.
I recommend to anyone still running win7 to move to win10. The longer you run win7 the more problems you are going to run into with new software, games and drivers as time goes on.
Windows Media player isnt the defaut, but can be changed to it & it not just plays but will rip CDs...
What it wont do is play Blurays... but thats a different kettle of (not our license so we aint paying) fish!