You might need to get the v9 install files, and point your uninstall message to those files. It's a minor hassle, but you should be able to get it from File Connect. You'll need a valid serial number.
https://fileconnect.symantec.com/
You can also get to File Connect from the Licensing Portal. Login with your account, and click on "Get Software" on the header. This is also a good place to retrieve license numbers if you've lost them.
https://licensing.symantec.com
I'd recommend downloading v9 from there, and using that in a directory as media to help uninstall. If that doesn't work, consider reinstalling this copy of 9 on top of your install, then uninstall it. (Think of it as a repair install)
If it completely refuses to uninstall - and this is causing other problems - you may need to resort to MSIZap. Now, be careful with this utility. It won't uninstall the program. All of the files and registry entries will remain, but the entry in the "Add/Remove Programs" list will be removed, and any program that senses if a program is installed will think it's not there.
http://msdn.microsoft.com/en-us/library/aa370523.aspx