You probably have a permissions error on the HKLM\SOFTWARE\Classes key in your
registry. Likely something has blown away all the proper users and replaced
them with Everyone. I originally had this happen (the cause, a Flash8 MSI
install) and boy was it a real PITA figuring it out. This will allow flash to
only work for the person who originally installed it.

The permissions problem is limited to Adobe's Flash Player install process,
which creates registry keys that grant permission to only one user. Why should
we follow the link in the previous message to do mass changes to registry keys
when the latest Flash Player 9 will recreate registry keys with limited
permissions? This has happened on one home PC and one work PC both running
Windows XP SP2 with latest upgrades. I've reported this to Adobe support and
have been waiting since Jan. 3, 2007 for a reply.