If we need to hide System Views in MS CRM 4.0, then we should write a plug-in code which is time consuming. If you want to do it quickly, then we can hide the System Views with SQL update (unsupported)
Example:
If we want to hide ’Opportunities Closing Next Month’ System View from Opportunity entity then use the below mentioned SQL update statement
update SavedQuery set IsPrivate = 1
where Name = ‘Opportunities Closing Next Month‘