C#.Net can't add the vixDiskLib.dll into our Project

Hi

I developing the pluing for access the VMware virtual machine. I am trying to access the virtual machine. So i am download the VMWare SDK api for .net(VMware Virtual Disk Development Kit) and am trying to add the vixDiskLib.dll , vixDiskLibVim.dll & vixMntapi.dll. But I can't this assembly in my Project. Let me know any solution for this problem.

Note : I attached the screenShot of Error Message.