Error message adobe flash player 3.0 r0--in Firefox

Internet Explorer uses the ActiveX variant of Flash Player.  Firefox uses the NPAPI variant.  If you only have the ActiveX version installed, that would be problematic.

That said, the description of the behavior you're seeing is really strange, but does not indicate to me whether the NPAPI Flash Player is or is not installed.  I've never seen the browser "delay" a page because Flash Player is not installed (particularly with added UI).  

A screenshot would be illuminating.

How to create a screenshot in the Adobe forums:

https://forums.adobe.com/docs/DOC-7043#jive_content_id_How_do_I_attach_a_screenshot

Hello, I am also running 32 bit Vista and using the latest Firefox 50.0 with the latest Flash Player 23.0.0.207 (go to Firefox Add-ons > Plugins and click "More" link for Shockwave Flash to see if that is your exact version), but I have not seen any problems. If you are seeing an error message every time you open the internet, what does the message say? What is your home page, and have you tried setting a different home page? Perhaps you should be posting at Mozilla Support?

Firefox will be the last major browser to support Vista when support for Internet Explorer 9 (and Vista) ends on April 11. I could name a few alternative browsers that support Vista, but I couldn't really recommend one. You could uninstall Flash Player ActiveX if you never use Internet Explorer, but that will not solve any problems with Firefox, which uses the NPAPI version. You don't need a subscription to install Flash Player.

Edit: Your processor is slightly below system requirements: Adobe Flash Player | Tech specs .