RAM can be an important factor. You really need 500 MB to be on the safe side nowadays.

When you use LW do you use the Resume function. I'd strongly advise against using it to continue multiple downlds on a dial up connection & particularly if you don't have lots of ram. It will rob LW of its connection quality & use up LW's resources & perhaps your comp's if you used the Resume button on many files.

Settings changes: Tools>Options>Speed & tick to disable the ultrapeer capabilities. Press Apply button. On uploads reduce your upload bandwith to 2.3 KB/s or less. Set your downloads to automatically clear. Delete search results more than a few hours old. Close/Hide windows you are not using at that time (eg: connections, library, monitor windows.) Use the View menu to do this.

Which version of Java do you have? You can find out by going to LW's menu > Help & choose About LW.

Delete LW Preferences folder whilst LW is closed. Instructions here: Fixes for Limewire

Fabion beat me to the button.