The answer posted above is only hypothetical. The details you havev submitted, just tells which OS you are using. With that OS, the limitation will be 4GB or more if you certain option called PAE.
The 16TB RAM listed in the previous comment, is what OS can address. What machine can take, depends on which mother board and Chipset you have.
You should check with mother board manufacturer for the RAM recommendations.
Is this a forum for technical issues or e-bay?