My sister has an old Dell running XP sp3,,she has never had a problem,,,until now. She says this has happened only Twice. Computer just sitting,,nothing on it but the screen saver,,all programs are closed off she's finished for the day. When she notices a box about 4in. long and 3in. high.,,tan in color with the blue xp strip on the top. Inside is a white mail envelope with a purple circle with the Yahoo Y in it. On the bottom of the box are 2 buttons,,like ok and cancel,except there is no words at all anywhere. She presses buttons,,,nothing,,she clicks icons nothing except the "move here"menu pops up. She opens MSE from the taskbar ,it says "not enough storage to run application. She clicks Start,,Control Panel,,and it says"can not put shortcut here." She hits "log out: it logs out,,then she logs in and all's ok. Computer works great. This is the secound time this has happened. I have no idea. Any thoughts from beyond????