How do we do this?
First you need to connect to the SQL Instance you wish to configure using SQL Management Console, in my example it is SQL 2012.
Next right click the instance (in my example my SQL Instance is called SCCM) and click Properties.
On the left of the properties screen click Memory. There will be a value by default under Maximum server memory (in MB) set to 2147483647 is equivalent to 2048TB of memory (no server has this!).
Set it to something more practical like 1024MB. Please note if you have a busy SQL application you will need to assign an appropriate amount of memory for the given application.