Click on the link to Sun's Java below, then scroll down to the ''Java Platform Standard Edition JDK 6 Update 24 (JDK or JRE)'' section, then click on the "Download JRE" button. Follow the prompts, select the Windows platform and the "Language", if necessary, accept the license agreement, click the "Continue" button, then download the full ''Windows OFFLINE Installation'' file to your desktop,(about 15 MB), scan it with your antivirus (just to be sure it's clean). Once that's done, if you've already got a Sun Java version on the computer, open the Control Panel, double click on the ''Programs & Features'' section, then uninstall all previous versions of the J2SE Java listed there. Once that's done, then install Java JRE 6u24 from the downloaded installer.
Hope this helps.
When I open the Java that I downloaded and saved when I get to Java setup the following message pops up: The software has already been installed on your computer Would you like to reinstall it ? yes or no. If I select no the setup stops and if I say yes I get the following message from windows installer: This action is only valid for products that are currently installed. I am using win7 64bit