For the past few weeks, security experts have warned that recently-discovered security flaws in Java were so dangerous that you should uninstall Java from your PC.
Oracle, the company behind Java, has now issued an update for the system. It corrects 50 separate security problems, many of which could have allowed hackers to gain remote access to your PC.
If you deleted Java, it's now safe to reinstall. If you didn't uninstall Java, you really should uninstall your current version and then head to www.java.com to get the latest release.