Here's how I reproduced this: Connect an external hard disk via USB to a Vista system On the Vista, scan a Windows partition on that hard disk Vista won't let you write to certain folders belonging to the Windows installation from the external hard disk, \Documents and Settings being one of them. If NOD32 finds a thread in that folder, it won't be able to delete the file (and Vista won't popup to ask for permission, either) and will display a "Retry/Cancel" dialog box if you want to Delete or Clean the threat.. At that moment, run Explorer, go to that folder, get permission to delete files, and delete the entire directory that contains the file with the threat Return to NOD32, click Cancel, then Pause. NOD32 will never actually pause the scan. Trying to Stop the scan has the same effect. The screenshot below was taken one hour after I pressed Pause.