Unable to allocate 4096 MB of RAM: Insufficient system resources exist (0x800705AA) Hyper-V Error

I created a Hyper-V VM in my Windows 11 PC. When I try to start the VM, it throws the error message “Unable to allocate 4096 MB of RAM: Insufficient system resources exist (0x800705AA)”.

Here is the first thing I did to try to fix this problem

  1. Open Windows registry editor: right-click the Windows Start menu and click Run. Then, type regedit and click OK.
  2. When the registry editor opens, navigate to:
HKEY_LOCAL_MACHINE\Software\Microsoft\Windows NT\CurrentVersion\Virtualization
  1. If the Virtualization sub-key is not in the CurrentVersion key, create it: right-click CurrentVersion, point to New → Key. When the “New Key #1” is created, change the name to Virtualization.
  2. Right-click the Virtualization key, point to new, and select
    “DWORD (32-bit) Value”.
  3. When the new DWORD Value is created, change the name to MemoryReserve
  4. Finally, double-click the MemoryReserve DWORD (32-bit) Value. When it opens for editing, select the Decimal option (beneath “Base”), then enter 2048 in the Value data box, and click OK.
  5. Close the registry editor and restart your computer.
  6. When your Windows 11 PC restarts, try starting the VM again.

Unfortunately, the steps above did not fix the problem for me. For now, what I did to fix the problem is to restart my Windows 11 PC. Then, after restarting my Windows 11 PC, I was able to start my Windows 10 VM successfully.

Unfortunately, this is not a permanent solution, as I received the “Unable to allocate 4096 MB of RAM" error the next time I tried starting the VM.

So, I had to restart my Windows 11 PC again.

This means that restarting the Hyper-V host PC is not a solution; it is, at best, a walkaround.

If you find a permanent solution to this error, kindly share.

Eventually, I was able to fix this problem by reducing the amount of RAM assigned to the VM from 4096 MB to 1024 MB.

But there is one more important bit: if the VM already saved snapshots, select the Continue option when you start the VM. If you select “Continue”, the VM will not start with the most recent snapshot.

However, if you select “Revert”, the VM will load the most recent snapshot and revert to the previous memory size of 4096 MB. If this happens, the VM will fail to start again.