Troubleshoot installation macromedia flash plugin for Internet Explorer 7 in Windows Vista
First you can try to uninstall Adobe Flash player if you have it installed. If you can't uninstall it, go to http://kb2.adobe.com/cps/141/tn_14157.html for more instructions on how to remove Adobe Flash.
If you do not have Adobe Flash installed on your computer, or the above instructions do not work. Read my instructions below. Go to:
C:\Windows\System32\Macromed\Flash
Then right clicked on both 'Flash9b.ocx' and 'FlashUtil9b.exe', and choose properties.
In properties choose the 'security' tab > Click on the 'everyone' user account, and at the button called 'edit' and then tick the box called 'allow full control' and also choose your own Windows local account name.
Once you have done this for both files run the FlashUtil9b.exe and it should install and update and tell you to restart.
You can also try switching browsers like Firefox, Google Chrome, Opera, or installing IE8 or IE9 on Vista to use Adobe Flash Player.