so its not a client side configuration...
you need to open up the virtual machine configuration from vCenter.
What you will actually need to do will vary based on the type of vm you have and how it has been provisioned to you by View... but assuming its a statically assigned vm, then you can go to vCenter - shut down the vm (ie power it off), then right click on it and Edit Settings. On the Hardware Configuration tab, I presume you will see 2x serial ports listed there. You need to delete them.
then power the vm back on, and log back in via the zero client.
if its a pool that is provisioned then you need to edit the vm template, and reprovision from there.
make sense?
cheers
peterB