You'll need to delete the registry folders for DivX from the machine (be sure to get both the local and user level folders).

To do this go to start > type 'regedit' in the run box > delete the software/divx folders from the registry of the local machine and relevant user accounts.

Once this is done run the installer file again (you do not need to uninstall first) and it will offer you the option to select an install language again. Select the correct language and complete the install as normal.

Reboot and you should find the problem corrected