In one of our server audits it was discovered that only one third of the memory has been allocated to the sqlserver instance. Questions were asked whether multiple instances of sql server are present. But when there was no other instance of sql server running it was recommended that we increase the memory allocated to double from 10 GB to 20 GB.
1) RDP to the SQLServer and sign on
2) Open up SQL Server Management Studio
3) Select the SQL Server in the Object Explorer on the left
4) Right click and select Properties
5) Select Memory tab as shown below
6) Change Maximum Server Memory from 10240 to 20480
7) Click OK
Close Management Studio
As a precaution restart the server. It is better if you do it after hours.