I have a somewhat new (June 2013) HP laptop originally running Windows 8 Pro. I installed the Hyper-V component right away and it was running great. After testing Windows 8.1 Pro on another computer a couple months ago, I decided to upgrade my HP laptop and Hyper-V continued to work great after the upgrade.
Yesterday, after a Windows Update failed, I was not able to boot my laptop. It would hang with the HP Logo and spinning circle at the point when the Boot Manager normally starts up Windows. Trying to do a recovery reported a failure, but no specific reason except to say boot failed and that a Restart might correct the error, but it would just hang on the HP Logo every time I would try to boot. I reinstalled the Windows 8.1 Pro OS and the laptop was working fine until I would install Hyper-V.
I have gone thru this sequence 3 times. The first time, I pulled the latest Windows Updates, then installed Hyper-V, IIS and some other components and after this install required a Restart, my laptop hung at the HP Logo. The second time, I did not enable any Windows Updates, but installed Hyper-V and IIS and again, after the Restart my laptop hung. So, the final time, I only installed Hyper-V and after the Restart, my laptop hung once again.
Since Hyper-V used to work, it would not seem to make sense that I have a hardware compatibility problem. I have also run the extensive built in firmware Disk tests and other diagnostics taking several hours to complete and these all passed.
I am now using my laptop without Hyper-V and it is working fine, but I hoping to find a reason/solution for the problem caused by installing Hyper-V so that I can once again install and use it.