I "accidentally" downgraded my Flash player 8 (web browser plugin) by
installing an older version of Flash Player. I uninstalled the Flash Player,
and ran the auto-installation for both Firefox and IE. Firefox installed
successfully, but IE never did. I have tried many times even left my computer
for a few hours but it never finishes installing.

Now everytime I visit a web page (using IE) that requires Flash 8 it always
asks if I want to install Macromedia Flash 8, but everytime I click yes it is
never successful.

Can I just download the installer from another PC and try to install it on my
PC?

Please help.