The 8.1 drivers are now up.
 
http://www.roland.com/support/article/?q=information&id=63060593
 
They cover both 32bit and 64bit systems. 
 
I am a happy camper this morning!

Woot! Thanks for this. Now I can finally update. :D

Thanks for the heads up on the Drivers, I have both a V-Studio 100 & an old UA-25EX and I'm just delighted to see that within the first week of the release of the new Win 8.1 update we have drivers that allow us to continue using our device(s).  Well done Roland, great support for your products & clients!
Cheers,
Wolf

Hi  - I'm wondering how the VS-100/Windows 8.1 combination is working for those that have tried.  I've had a strange issue I would love to have some feedback on.  When using  Sonar X3 I can only get the the default setup.  For example the sonar X3 wave profile sees only channels 1&2 at 44100hz. X3 seems to work fine as long as I stay within those bounds.   I know this is not only a VS-100 issue as I get the same thing when I installed a Focusrite Pro. The Focusrite defaults to 48kHz however so the 44kHz files won't play.  This has  not been an issue with Windows 8. My computer is fairly old - Intel Series 3 chips I believe from 2007.  I was able to get everything happy in device manager but it too a little doing. Windows 8.0  was never a problem.  Maybe my problem lies there.  I'm wondering if my experience is unique? 
Thanks
Tim

Hi tbeach. 
Welcome to the Cakewalk forums.  I see we joined around the same time in 2003. Wow-10 years.
Make sure that you turn on the Vs100 before you start Sonar.  Then do a wave profile and see if it picks up the channels.
And you did install the new 8/8.1 driver released around November 1st, yes?  Good luck.
 
You might post the problem in the main X series forum for help also- a bunch of smart users to help you.

There are issues going from Win 8 to 8.1 for some drivers.  Have you tried to disable the sound card or on board audio, then install the drivers for V Studio 100 and run setup again?