There are some threats that impersonate legitimate programs, modify browsers or the boot screen graphics, and even redirect traffic. Our standard scanners necessarily have a delicate balance between effective malware detection and removal and erroneously removing legitimate files. Sometimes, these "scareware" programs can require special tactics to remove them.
With the Norton Power Eraser tool, these threats (and others) are specifically targeted, and thus are effectively detected and removed. Users should use the Norton Power Eraser utility when nothing else will remove an annoying software and they are are willing to accept a higher risk that the scanner may quarantine a legitimate application.
Program should be considered for advanced users. It can be very aggressive and remove programs you might not want to remove.