Third Windows Technical Preview build, build 9879 was released today (12-NOV-2014). The sysprep method described in this tutorial has worked perfectly from Vista to W10TP build 9860 but this latest build seems to have issues with it. The method does not work, I have now tested past hours all possible scenarios.
I believe this is a temporary issue and will again be fixed in later builds. I also continue searching for a solution. In the mean time, please do not use this method!
For now you can use the registry editing method as told in this tutorial on our sister site the Seven Forums: User Profile - Change Default Location - Windows 7 Help Forums
I have tested the above method now with build 9879 and it works without issues