When Hyper-V is enabled, boot phase always stops at the login page on

 AMD Phenom(tm) II X4 965 Processor
 AMD64 Family 16 Model 4 Stepping 3, AuthenticAMD
 HYPERVISOR - Hypervisor is present
 SVM * Supports AMD hardware-assisted virtualization
 NP * Supports AMD nested page tables (SLAT)
virtualization enable
 ga-ma78gpm-ud2h/ga-ma78gm-ud2h{us2h} Gigabyte  motherboard

Hi,

Did you mean that host machine stucked during boot phase when Hyper-V enabled? Or Virtual Machine boot failed?

If the first situation, have your tried any method to resolve this problem?

How about using WinPE or Windows installation Dic to repair it?

Please provide as more as detail for your problem so that we can  resolve this problem more effective.

You mean it's hanging on boot?

You have a Gigabyte board.  There are a lot of issues with Gigabyte and Hyper-V.

One thing you can try is disabling USB 3. http://support.microsoft.com/kb/2693144

Also check with Gigabyte for BIOS updates.