following instructions provided by essexboy. attached OTL log after running the fix. I noticed that C:\Windows\Installer\{1d8cfe9b-a373-289f-0e75-d1c34635c803} folder still exist after reboot, so I restart Win7 in safe mode, but still can't delete the folder. I still see pop-up windows regarding this malware-gen. I wll run combofix and post log next.