How can I convert a virtual machine to a virtual machine? It is actually a Windows 2000 running on ESXi 3.5 and to convert it to a virtual machine running on ESXi 6.5
you can export it to ovf/ova and then import it into esxi 6.5. this is assuming you are using vcenter server. if not you could attempt doing a v2v using vmware converter
From the looks of it ESXi 3.5 should be using hardware compatiblity 4.
https://kb.vmware.com/kb/1003746
and ESXi 6.5 supports the running of VMs with hardware compatibility 4.
https://kb.vmware.com/kb/2007240
So in theory there should no need for conversion but simply an export/import or even simply a copy to the ESXi 6.5 datastore. You may want to upgrade the hardware compatibility once the Windows 2000 VM is inside the ESXi 6.5 although it is unlikely it can benefit from any advanced features of a newer virtual hardware compatibility.
Have you tried Converter? W2K is not supported as it is too old, but a V2V is expected to succeed. In case of errors after 97%, just power on the VM, it should be able to work w/o reconfiguration.
You do not need to do anything special at all.
Simply upload the complete directory in case that is necessary.
Then register the VM.