Have you tried with the resident protection part of your AV turned off ?
Have you tried in safe mode ?
Have you given the relevant permissions to your firewall ?
If you have but to no avail, then it could be that your existing installation of Java is corrupt.
If so, go control panel>add or remove programs and uninstall that current version. Then go c:/program files and delete any residual Java folders....then go c:/program files/common files and delete any Java folders.
Reboot and then do a clean install of the latest version........would recommend a clean malware free version from filehippo
http://www.filehippo.com/download_jre_32/