Updating the flash player does not seem to clean out all files to do with older versions. Maybe that is a bad thing, given that there are some nasty exploits of old flash players. Also, sometimes I want to clean out a machine and put a certain flash player on it for testing.
To get rid of old flash players you need an un-installer that can be downloaded from Adobe.
Older versions of flash player are available from Adobe's flash player archive .You might want and older version for testing - it is not a good idea to use an obsolete player for general use, because of the danger of it being exploited.