I should have said I'm using a Mac. I've tried doing this for a Mac and it says "Uninstall Abode Flash Player" is damaged and can't be opened. You should eject the disk image.
This is a Gatekeeper issue. Flash Player files downloaded from adobe.com or macromedia.com are correctly signed with a valid signature, however, it appears Gatekeeper on your system is having issues with it. Please see the following:
- OS X: About Gatekeeper - Apple Support - scroll down until you find "Damaged" app
- Mac Kung Fu: Dealing with "damaged and can't be opened" error messages
An internet search for "is damaged and can't be opened" will return many more results.