Found this trick on WinAero
You can do the same thing with group policy if you have a version of Windows that supports that. See the TenForums link for details
To Turn On or Off Including Driver Updates in Windows Update
"The oraenv is not meant to be run from the Grid Control 184.108.40.206 Agent ORACLE_HOME.This was diagnosed in BUG 10227734. The BUG will remove the oraenv from future agent installs....
Set the environment manually or using .sh script."
$ cd $ORACLE_HOME/rdbms/lib $ make -f ins_rdbms.mk dv_off ioracle
\bindirectory, rename the
oradvll.dllfile to another name, such as