Let's try one last thing. Open Internet Explorer and go to
http://www.adobe.comGo to Tools - Internet Options from the menu at the top.
Click on the Security tab. Click on Trusted Sites under zones then click on the sites button. Uncheck the box "Require server verification". Under "Add this website to this zone" adobe.com should be listed. Click the add button. Click close then apply to the next box. Close IE.
Open IE and go to
http://www.adobe.com/products/flashplayer/Try installing flash player. Hopefully it works.