HKLM\SYSTEM\CurrentControlSet\Services\AtmUni\Parameters\Adapters\<Adapter-GUID>\
The Parameters subkey under the <Adapter-GUID> subkey stores configuration data that applies only to the ATM network adapter represented by the subkey.
Some entries can appear in the AtmUni\Parameters subkey and in an <Adapter-GUID> subkey. If the entry appears in both locations, the value in the <Adapter-GUID> subkey takes preference over the value in the AtmUni\Parameters subkey when configuring that particular adapter.