It is important to note for EVERYONE who is having issues. Once your update is done and computer has restarted etc, go to Windows Update and run updates. The issues you are all talking about have been addressed and there are at least 2 updates since the Build 9860 was released. SO, Before you note the problems, make sure you install the updates after the build upgrade.
Instructions followed to every detail. But still my trusted antivirus is having trouble to keep Build 9860 on my laptop, secure. It is actually now warning me: Your Computer Is At Risk! Wondering if this issue is specific to my system alone.
My suggestion would be, don't use a 3rd party Antivirus program. As with Windows 8 and 8.1, the Tech previews come with Windows defender which has been upgraded to include Antivirus as well as spyware. Until a final release is done, it is probably that other programs won't function properly.