That's a little bit vague. Can you be somewhat more detailed, so we can see what you do and what happens.
Like:
1. In Firefox I type www.adobe.com in the address bar.
2. On that page I click on Flash (bottom right)
3. On the next page blank the checkbox to install McAfee Security Plus and click on Install
etc.
Kees
I've been trying to download flash player on Firefox. Nothing works. Any help ? Thanks I have Vista

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