Installing JRE under custom setup environment to a changed drive fails with different error messages. For details read below.

Exact Steps to Reproduce:
Step 1:
Download JRE 5.0 Update 8 from:
http://java.sun.com/javase/downloads/index.jsp
Download Type: Windows Offline Installation, Multi-language

Step 2: Click on executable to run the installation process.
Choose the "Custom Setup" option and click on Accept.

In the Custom Setup dialog box, click on "Change" in the bottom right corner
and change the install directory to drive "C". (See attached screenshot- install_setup_dialog.jpg)
Note: You can switch to any other available drive as well.
Click on "Next >"

Step 3: In the browser registration dialog box, keep the default listed browsers
enabled. Click on "Next >" will begin installing JRE 5.0 Update 8

An error "Error - Java(TM) Update" - Neither command line parameter specified
is an existing directory. (See attached error screenshot - install_error01.jpg).
Click OK.

Another error dialog will appear "Error - Java(TM) Update" - Java(TM) Update
fails to apply changes to your system. (See attached error screenshot -
install_error02.jpg). Click OK

This time "Error 1722" dialog box will appear. (See attached error screenshot
- install_error03_1722.jpg)
J2SE Runtime Environment 5.0 Update 8 Installer - Error 1722. There is a
problem with this Windows Installer package. A program run as part of the
setup did not finish as expected. Contact your support personnel or package
vendor.

Click "OK" will bring forth Installation Completed dialog box. Click on Finish.
For reference see the log file (jre_install.log) as attached.

Step 4: Go ahead and check Windows Control Panel - There is no Plug-in icon registered.
However, the program is listed in the Add or Remove Programs.

This bug is always reproducible.