Failure to uninstall completely

[Jacky_go3]

After i follow the proper step to uninstall and install a new version 3.6.3, it pop-up a webpage "http://shark007.net/forum/Thread-Setup-and-usage" and said i do an upgrade install. I try repeat the step but it keep happened.
Alternatively, i try to install other codec package after proper uninstall but it alert me Win7codecs is currently installed on my pc and me uninstall it, then i click 'yes' to uninstall it show me error message.
I prefer to use Win7codes even it said i do upgrade install but now i found an error i.e. some rmvb files can only play with sound no image is display, such rmvb files also failure to generate thumbnails.