My wife's elderly aunt lives next door and acesses our router from her computer which was running Windows Vista. About 4 days ago her Windows desktop lost it's background image and the only icon on the desktop was the trash can. No pictures or documents would show up when I typed 'winfile' in the Start Menu search box, just a backup file. (I later found that the files had their attributes set to hidden, and was able to restore some of them to visibility by unchecking the hidden flag under the Users directory, but some files were missing). Microsoft Security Essentials tried to clean the trojan it found (DOS/Alureon.E) but could not. I tried several of the recommended techniques and utilities to remove it but none worked. (Kaspersky, BitDefender, etc.)
I had an upgrade disk for Windows 7 so did the upgrade and chose the option to install to a new directory which puts the old Vista directory under Win.old. After the installation and reinstalling Microsoft Security Essentials, it showed up again, but the partition of infection was also displayed. In my case it was partition 3 of 1GB size. As a last ditch effort before reformatting the drive or replacing it, I deleted the indicated partition, reran MSE and it indicated no infection. This requires accessing the disk manager located by right clicking Computer in the Start Menu, then choosing Manage, then disk management. If MSE indicated the infected partition and it is not the boot partition, you also may be able to remove it (it was created by the trojan).
Edited by hamluis, 17 April 2012 - 09:59 AM.
Moved from Win 7 to AV, Firewall, etc.