I recently upgraded my development environment (Windows 2000 professional) from JDK1.3.1_02 to the latest Sun JDK1.4. Everything worked fine while developing applets, servlets, EJBs, etc. but when I attempted to use my development machine as a web client, the browsers (IE6 and Netscape 7.01) were unable to process any Java enabled pages. (my own and Yahoo web pages with Java applets on them asked for a download, and then provided a link to Windows Update - this route (through Windows Update) to download required JRE software did not work, i.e. Windows Update thinks I already have the required software). To fix this problem, I had to uninstall JDK1.4 and revert to JDK1.3.1_02, after which, everything worked perfectly. My questions are "What is going on here? How do I successfully go about upgrading my environment to the latest JDK?"