Run into this annoying issue trying to convert a Server 2008 RC2 VM to an ESX server.

Nice simple fix. Run Convertor as admin.

NOTE: This is relating to a Physical machine to Virtual. But this fix worked for me where my server 2008 R2 is Virtual in VMware Workstation and wanted to move it to an ESX box.

http://musumeci.blogspot.com/2010/09/vmware-error-specified-parameter-was.html