Put another 512 MB of RAM in it. RAM is a very easy upgrade and if you have less than 1 GB you will notice a speed boost if you upgrade to 1 GB or more.
The meaning of good or not good depends on the usage you do to that computer, if you only us it for surfing the web, running word prcessor and spreadsheets the it is fine.....everything depends on your needs....
get more ram Get 2 1 gig sticks there cheap enough now, See if you can find "Klipsch" ram I hear it blows all other ram away..... I'm kidding about the Klipsch but 2 gigs should set you straight, perhaps a nice video card might help you out if you want to play a few games!
Depends on what your using it for. Just to go online and mess around with different applications is fine. If your looking for gaming its not for you but just to mess around its fine. What do they want for it?