You also might consider upgrading some time soon Picard.
Though, since you've waited so long that might be tough. Procs for s939 are becoming harder and harder to find at a decent price.
You might have to start putting some money aside every month. For just over $300 (not sure what that'd convert to in your currency) I built my older sister a fairly decent rig- though she's using on-board graphics. Maybe build a comparable rig using onboard until you save up enough money to get decent dedicated graphics.
Either way- you're system is old. In another year or two it might struggle running Office.