There is no such thing as Adobe Reader 8.3 - from where did you get it?
Whereever you got it from, try to remove it with the Windows Installer Cleanup Utility; use Google to find a download location, as Microsoft does not longer support it after June 25th.
Sorry - It is actually 8.1.0 tries to go into setup when I try to open a PDF file.
Try and remove it from Control Panel. You may have to reinstall version 9.x afterwards (the uninstall could break it).
If you cannot do that, download, install and run the Microsoft Installer Cleanup Utility to get rid of any traces of version 8.x then reinstall 9.x.
9 should have removed 8 during the install but obviously it didn't work as planned.