As magasvs stated, a little bit more information is needed before suggestions or advice can be given.

What OS edition and 32 or 64 bit?

What SQL Edition (Enterprise, Standard, etc) and 32 or 64 bit?

There are numerous post on SSC and MSDN that deal with memory settings on SQL Server. A major player in the decision making process is what OS version you are running and if 64-bit or 32-bit.

If you are running Enterprise edition of OS and SQL on a 64-bit one of the main configuration settings you need to work on is the min and max memory settings for SQL Server. The AWE setting does not come into play on a 64-bit SQL instance. I would suggest utilizing Performance Monitor (perfmon) to find the happy medium on how much memory your instance of SQL is wanting and actually using.

The memory usage can change over time depending on what type of application is running against SQL Server, so you should always review this information frequently.