I would like to share the solution to this error scenario:
I’ve upgraded my Win7 Pro 64 bit to Win8 Pro 64bit and then installed WinPhone8 SDK.
VS 2012 and TrendMicro antivirus were already present.
When you run your WP8 app in debug mode on the WP 8 emulator, it does not start and displays this error message: “The Windows Phone Emulator wasn't able to set some properties on the virtual machine: Couldn't
change memory of the virtual machine: Error code 32775”
The main issue seems to be already known to those who already worked with Hyper-V on a machine with TrendMicro antivirus installed. The same happens with other antivirus programs as well.
Trend Micro description: “The root cause is that Hyper-V uses non-cached I/O requests while the real-time protection of antivirus software often uses mapped I/O requests.”
You can find the suggested solution in these posts:
Does OfficeScan 10 support Windows Server 2008 Hyper-V?