To work around this issue:
- RDP to virtual machine using the mstsc.exe
- Increase the keyboard class buffer size in the virtual machine
- Disable the synthetic keyboard in the virtual machine to force using the emulated keyboard
To Increase the keyboard class buffer size in the virtual machine
1. Logon to a running virtual machine as an Administrator.
2. Hover mouse on the right hand side top corner, Click Search, Type regedit, and Right Click on Registry Editor, Click Run As Administrator.
3. Locate and then click the following registry entry:
4. In the details page, double click: KeyboardDataQueueSize
5. Select Decimal and type a value data of: 1024
6. Click Ok. Close the Registry Editor. you can modify the same registry for a group of Hyper-v virtual machines using GPO. GPO location is Computer Configuration/Windows Settings/Security Settings/Registry. Right Click and add new registry.
To disable the synthetic keyboard for a virtual machine
1. Logon to a running virtual machine as a member of the Administrators group.
2. Hover mouse on the right hand side top corner, Click Search, Type devmgmt.msc, and then Right Click on device manager, Click Run As Administrator.
3. Click Keyboards, right click Microsoft Hyper-V Virtual Keyboard and click Disable.
4. Close the Device Manager snap-in. Restart Virtual Machine.