Java is needed by some websites in order for you to actually view them, and other sites with games for example yahoo pool, you wouldnt be able to play that without java installed.

http://www.filehippo.com/download_java_runtime/ click on that then when your on the site click on "download lastest version" at the top right, this will install the lastest version and it will stop you from being nagged about installing it plus you wont have any probs with sites loading up that require java