I have an XP/32 SP3 system using IE8. I use the latest Avast, and have realplayer 16. I temporarily disabled all add-ons today, and subsequently I have been unable to re-enable as the entry has disappeared from the list of add-ons. I have uninstalled and re-installed IE8, ditto with Adobe Flash using the Adobe Flash removal tool, and then re-installed the latest IE version. I have used the Flash test option and the screen is just greyed out. So clearly although there are no error diagnostics during the install, the add-on is not being integrated into IE8. Hence URLs that require flash show an error.
All M$ updates uptodate.
What could I try?