I have the version 9.0c, but I want to use 9.0b, but the installer of
the version 9.0b does not install and says that directx already is
installed... Has some form of uninstall directx 9.0c to install
9.0b?

http://archive.forums.soldat.pl/topic.php?topic_id=18376


[ Portuguese > English, =P ]

google is your FRIEND http://www.nextwave.com.au/uninstall-directx-free-download.php i.e.

i suggest this http://www.majorgeeks.com/download.php?det=4347 tool

http://www.dxbuster.de/index_e.html

or: http://www.3dcenter.org/downloads/directx-dx9uninstaller.php

There is no way (read as good way) to uninstall an older DirextX version, except by re-installing Windows. Too bad, actually...

Oh, adorable search
USe directx eradicator
http://downloads.guru3d.com/download.php?det=626