DirectX error

how to fix DirectX function "m_deviceContext->Map(m_externalValueConstantBuffers[StageIt];0, D3D11_MAP_WRITE_DISCARD,0, & mapped Resource)" failed with E_OUTOFMEMORY ("Direct3D could not allocate sufficient memory to complete the call.") GPU:"Intel (R) HD Graphics 4000", Driver: Unknown. Free virtual memory: 37316kb/2097024kb. Total resource memory: 0kb. Make sure you have a supported graphics card with atleast 512 MB.

PLEASE HELP ME HOW TO FIX IT.... THANKS....