General Description : When installing over an existing installation, the install program may not let you proceed from the step of choosing a destination directory.
解决方案
This can be seen when the user is re-installing the 3.1i tools to an existing 3.1i directory.
The workaround is to remove the $XILINX/bin/hp directory and begin the installation again. After this is done - the latest service pack should be re-applied.