Frequently during quiet periods while online, data downloads occur as can be observed by the data transfer indicator flashing on the modem. They have not been preceded by requests for updates, requests for specific downloads, or by announcements from any source. They usually resume if the modem is switched off for a while, and then switched on again. 50 MB has come down over the last half hour. There is usually no warning from my firewall and other security software, which does not mean that the downloads are definitely safe. This interferes with sensitive connections to banks, for instance. I have found no obvious clues while browsing folders, and there are many hidden folders in Windows 7. How can I identify the data online, preferably, or on my harddrive later ? Opening the Downloads window after the start of a session of mystery files does not help.