•Stop / disable the services in SQL Server (& others) that you are not currently using. It will minimize the memory utilization.

•Also, provide min & max memory setting in SQL Server configuration.

•Don’t use multiple programs (applications) at once.

•Add more memory, if possible.

For More:

http://technet.microsoft.com/en-us/library/cc917563.aspx

http://msdn.microsoft.com/en-us/library/ms178067.aspx