What type of error do you get?(If any)
You should try updating your Java software here:
http://jdl.sun.com/webapps/getjava/B...&host=java.com
Another thing that may be messing up is your cache. Just do this: Go to "My Computer", go to your "C:\" drive, and make a new folder named "rscache" and try to reload RuneScape.
If that doesn't work, and you have no more options, try selecting different Java versions at the RuneScape "Detail Select" page. Try the bottom selection in the drop down, "Unsigned Applet".
Is it an actual loading error or does it just go slow?