For Windows users, please follow the instructions below to upgrade to Mathematica 6.0.3:
Please uninstall any older version of Mathematica 6.0.x that you might have on your machine.
To do this, please go to Control Panel > Add/Remove Programs and select any existing
Mathematica Version 6 instances from the list. If you encounter any
problems, please contact support.
After the uninstall, check if the Mathematica
installation directory still exists on your machine. If so, you
should manually delete this directory. By default, the installation directory is
(on a 32-bit machine):
C:\Program Files\Wolfram Research\Mathematica\6.0
(on a 64-bit machine):
C:\Program Files (x86)\Wolfram Research\Mathematica\6.0
Reboot your computer.
Now you are ready to install Version 6.0.3
If you have any questions, please contact support.