If you’re getting error cannot open the destination virtual machine for reconfiguration from VMware Converter standalone, this means that it cannot connect to your ESXi host.
To fix this, check the network connectivity, user credentials and any other settings relating to copying and creating a vm in your environment. Also try deleting the existing vm and let it make a new one. Or try making a new one and copy into it. Make sure the vm is correctly sized.
Also, if you’re still struggling, you could install Windows and SQL server into a VM, then backup and restore your SQL databases into the new server. That way, you can take the opportunity to upgrade your old operating system to a newer, more secure operating system that’s supported for longer.
Alternatively, if you still get the error opening the destination virtual machine, you could do an image based backup and restore it into the VM.