When installing 1.3.1_01a, the installer may fail to install properly if 1.3.1, 1.3.1_01, or 1.4 already installed on the system. Registry keys may not be set properly or files may not be copied if other JRE exists. The result is that users may see browser crashes, poping up "Java Plug-in Error Message", etc.

This problem occurs on various Win32 platforms, including XP, ME, NT, 2K.