For windows go to control panel. Then to system and security you will see Flash listed double click on it and you can select the radio button that says "Block all sites from storing information on this computer". Then you can go to the Delete All button close to the bottom and it will delete all the data and settings already stored on your computer. I hope this helps. I found all this information on Abode's website.
I have a popup tthat says Updateflashplayer and a series of numbers, it is a trojan bot and removing it and/or stopping it from popping up seems to be a bear. I ran windows security, windows offline security, malwarebytes and cccleaner - several times each. Reset Explorer also . Some suggest it was allowed in because I use firefox. Seems that all of the above has stopped it for the moment. Is this a similar issue to above? And if anyone has suggestions on how to stop it or get rid of it, I'm all ears.