Hi Grasshopper,

There is no "Disable" but "Deny" will certainly work for testing purposes.  I would eventually delete though or someone may come along a grant access.  In our Corp environment there are well over 100 users with some nested privilage under the Builtin\Administrators account so our policy is to setup SQL services with domain accounts, add the DBA group as sysAdmin, and then delete the Builtin\Administrators account after every setup of a new server.

John D