I just wanted to let you know that I have bad experience. I was tempted to update my non-music computer to Win. 8.1, it worked for a day and now lost power to all USB ports- can not log in. Please, see my post under computers section for more information or if you like to help. Thank you.

Yeah, I've been having similar issues with my PC, with drivers not loading properly (especially USB 3.0 drivers) and my computer randomly shutting off and restarting (usually at the worst possible times).  I'm seriously considering to going back to Windows 7!

After several attempts to download and install the 8.1 update my computer finally crashed making my C: drive invisible to my system. I have to reinstall to another drive. Effectively I've lost 2 days work as well as my 265 gb SSD drive as Win 8 says it's a GFS drive unsuitable for Win 8. Never mind that it was already installed and running fine on that drive until the 8.1 update.

Crazy - back to the salt mines. Haven't had to do this sort of mucking about since the win 98 days.

Should have just stayed on Win 7 - what's that you say "if it ain't broke, don't fix it".

I would always recommend a total clean install of Windows 8.1 on a fresh formatted drive.

Working fine here.

backwoods
Working fine here.

Works for me except I can't verify my account/PC.
If anyone above has to contact Microsoft Support then my heart goes out to you.

Grum.

How to do a clean install if I upgraded to 8.1 from 8 ? I have no Iso disk just windows upadte from windows store...

I've finally got 8.1 running. Phew!

I ran the Preview for quite while without incident.  Only issue was
my Quad Capture interface was non-functional.  Once Roland
release the updated driver for the QC I did the update and things
have been smooth.  Only issue I have currently is that in X3b, when
I attempt to adjust the faders with the mouse, they jump like rabbits
to the top and bottom.  Faders move fine with the mouse wheel, but
not when moving the mouse.  If I move the mouse as slow as I
possibly can, they will increment.  

Other then that, not issues...YET...

No problems here.
 
Got both my systems up and running with 8.1 with no issues at all
Just make sure your hardware's got win8.1 drivers released before the update and everything should work out fine