Guid Troubles

I'm having some trouble with a pair of machines that have the same guid, they are old dell latitude d610's. I've got a couple of utilities, if I use randguid or uuid I get the following error -

error number =30000081
it is pnp function error !
function number = 0
command number = 0
error happan in subroutine #0
error description :
pnp functions return code : 0x81, unknow, or invalid, function number passed.

Has anyone come across this before? been using both utilities for years with no problem.