First of all, memory usage should grow as the server is used. You purchased 2GB of RAM to be used, didn't you? <G>
On a 2GB server that's not running HTTP (you don't mention it), those usages don't exactly look out of line - except maybe agent manager.
If you suspect memory leakage, there are Windows resources available for using perfmon to determine which specific app or process is leaking.
However, have you used perfmon to do any information gathering on processes and CPU utilization?
What did the commit memory versus actual memory looked like before you rebooted????
Jon Johnston
Creative Business Solution
IBM, Lotus Premier Partners
http://www.cbsol.com