The memory allocation for the Wmiprvse.exe process keeps increasing when you update the membership rules of a collection frequently on a computer that is running System Center Configuration Manager 2007 SP1

Consider the following scenario:

• You create some collections on a computer that is running Microsoft System Center Configuration Manager 2007 Service Pack 1 (SP1). These collections contain many membership rules.
• You frequently update these rules by using scripts or by using the Configuration Manager console.

In this scenario, memory allocation of a Wmiprvse.exe process keeps increasing every time that you update these rules. Additionally, the memory is not released until the Windows Management Instrumentation service is restarted.

more info on Microsoft support