When it comes to selling your old digital equipment you usually should wipe it of all digital traces with something like DBAN, however if you can’t there are some precautions you should take–here’s one related to Flash content you may have viewed on your PC.
When you rent or purchase a movie over a service that uses Flash, it authorizes your PC to play that particular content. When you sell your PC, unless you deauthorize your PC, the new owner will still be able to view and play the content you purchased.
How to Deauthorize Flash Content
Right click in the bottom left hand corner of your screen to bring up the WinX menu and open the Control Panel. If you’re using Windows 7 you can just open the Control Panel normally.
Then switch from the default Category view to the Small icons view.
Now launch the Flash Player settings applet.
Then switch over to the advanced tab.
Scroll down to the bottom of the dialog, then click on the Deauthorize This Computer button.
Now go ahead and close all your web browsers before clicking on the OK button.
That’s all there is to it.