There are several other clients that will be less taxing on your computer system.

http://www.gnutelliums.com/windows/

In my opinion, BearShare (which is on the page I have given the link to) is a great Gnutella Client for the windows platform. It uses fewer system resources and should prove to be relatively fast. During the install, however, make sure you choose NOT to install Newdotnet advertising. It may cause conflicts with other programs on your machine (most notably LimeWire).

TO MODERATORS:
I realize that this is the LimeWire section, but this may help others who cannot run LimeWire with an older computer. Please don't relocate this thread. Thanks! :-)