Do you suspect spyware of any kind? It's not unusual for a process to take up 100% CPU time at any given moment, nor is it unusual to have that much commit charge. It's not unusual for explorer to take up that much memory, either. My box, with 1.5GB of RAM looks like this:
Commit Charge: 338M/2923M
...and if I open a program, CPU usage will spike to 100%, briefly.
So, you're right at a normal load, I'd reckon. My system runs fine with those numbers. Is something happening? Is the machine running slowly?
Poser uses a large amount of resources since it is a very processor-intensive 3-D modeler. Even top-of-the-line machines will slow under the demands of Poser. When Poser first starts, it will take every spare bit of processor time that it can to load everything up and get the program running. So if you notice that all your background tasks suffer slowdowns when the program loads, that is quite normal.
When you say, "I have to shut off alot of processes to get it to work", what kind of processes are you talking about, and are you saying that that Poser refuses to run unless you shut down those processes?
If you have to shut down background processes/programs in order to use Poser without Poser feeling extremely slow, then most-likely your system isn't fast enough to multitask Poser and those other programs.