When I convert a physical machine with WSUS to my virtual envirornment the CPU of my ESX get a 100%, if I turn its to a phisycal machine the was solved. WSUS can have some bug related to this issue?
Is there a difference in CPUs? Meaning does the physical have 2 CPU's and the virtual has 1 vCPU? If this is the case you'll have to change the HAL on the server to uniprocessor