I needed to get some Windows 2003 virtual machines migrated from a VMware Server 1.x implementation to an ESXi host (In my case, this was controlled under vCenter.). Here is the procedure I used that worked rather well despite some limitations. Note: this procedure was used to migrate Windows 2003 VMs.

Verify that you have no snapshots. If you do, remove them. Also, if you want maintain the same MAC address and IP address, you should note them before starting.

Shutdown the virtual machine from the VMware Server console.

Copy the VM over to your ESXi server (You need to have ssh enabled on the ESXi host.).

Add the copied over VM to your vSphere client inventory.

Use the VMware Standalone Converter to convert the powered off VM you just copied over. The destination is going to the same as your ESXi host (or any other ESXi). I did uncheck “Remove restore checkpoints”, but this should not be necessary.

Once converted, boot the newly converted VM.

Install or upgrade VMware tools.

Then, if you want to preserve the MAC address and IP address, shutdown the VM.

Modify the MAC address via the vSphere client by manually setting it in the Network Adapter settings.

Boot the VM.

Configure the static IP address, if you had one before the migration.

This process went very well and without an issue. However, you do need to be able to have enough space to have two copies of the VM on the ESXi host if you only have one ESXi host in your environment.