I have NIS 2011 on my wifes computer. Every morning when it does its scheduled scan it pops up an alert saying the MBR is infected with mebroot. I have run complete scans on the hard drive with NIS, Kaspersky AV Tool Kit, Eset Online Scanner, Malwarebytes, Super Antispyware, ComboFix, and OTl. The last with the assistance of online malware support forums. I have also installed the Recovery Console and replaced the master boot record 12, yes 12 times, and still get the annoying popup. With all these scans absolutely nothing was found on the system by any of them except she still gets the popup every morning. I contacted the FalsePositives section and they referred me here. The system is Windows XP SP3 with all updates installed.