I am running windows 7 64bit, and typically use Mozilla Firefox 5.0.1 however this problem also applies to Internet Explore 9.
I had several viruses and after cleaning them off and making various changes to my computer (deleting old versions of Java and other unnecessary programs) I opened up the Internet (Firefox) and discovered Flash no longer worked. Every page I go to with Flash content says I need to install the pluggin. I have tried numerous times (both using the firefox pop-up prompt and the adobe product page) to download and install the newest version of Flash (11.4.402.278), however, after the download and installation have competed (neither displays any problems) Flash still does not work. The Mozilla pluggin manager does not even show that I have any Flash pluggins, old or new, despite the fact that I perviously had Flash installed. I have tried uninstalling with the flash uninstaller and re-downloading and installing. I have made sure I am downloading the correct version (32 bit Flash Player for Mozilla) for my specs. I have tried turning off my anti-virus programs before downloading Flash. I have tried ensuring that my windows permissions are set correctly before downloading and installing. I have tried performing a clean install. I tried uninstalling and re-installing Mozilla Firefox. There are Flash files in both the system32 and syswow64 widows folders, but when I open add/remove programs in control panel Flash is listed but only has a generic icon picture (it looks like a page with the corner folded down) instead of a stylized icon like adobe reader and all of the other programs. The same problem occurs with Internet Explore 9 (I did make sure to download/install the Internet explore specific Flash Player, ect), which I never use, however, when trying to install Shockwave (because Shockwave content is having the same issue- it downloads/installs fine but will not work and doesn't show up as a pluggin in Mozilla) I checked the option to download and install Google Chrome and Flash is currently working fine in Chrome. Clearly the download worked since Chrome downloaded and installed fine.
I'm at a loss because I have searched and searched and found similar problems but all of the proposed solutions have not fixed my problem. Any ideas?