Have you been experiencing bad lag on your runescape client? if you have then go to this link and follow the 2nd step in the video!
Basically all you have to do is go on your task manager and go to to "processes" tab and scroll down till you see a - "jagexlauncher" with a large number of mb being used. Then all you need to do is right-click on it and scroll down to set priority and set it to high - this allows more of your RAM to be used on runescape making it less laggy and run smoother.
If you didnt understand this then here is a video that will help - its after 3 minutes that these steps are shown!
hope this helped!