If you're running Sunbelt's Vipre product, you'll want to monitor the support forums for more information. Information from several sources are indicating today as Black Monday, having to run system repair for get Vista and XP machines working again. The majority of the issues are affecting Lenovo computers, due to the way Lenovo installs additional utilities that aren't necessarily needed to function correctly. Vipre is recognizing utility executables as virus-infected files or malware and deleting them from the file system.
Support forum: http://supportforums.sunbeltsoftware.com/categories.aspx?catid=23&entercat=y