Regular antivirus tools are generally cautious about what they remove from your PC. And that makes sense - you don't want them disabling a legitimate program because they've misidentified it as malware. But at the same time, this caution means that occasionally they'll miss deeply embedded threats, because there's just not quite enough information to decide what they are.
Norton Power Eraser works a little differently. This portable tool uses aggressive methods to try and identify every piece of malware on your system, and this enables it to pick up and remove dangers that other antivirus engines might miss.
This does mean you may see several false alarms, however. Norton's site warns that Power Eraser "can select some legitimate programs for removal", and in our tests that's exactly what the program did, regularly picking up safe programs and recommending that they be deleted.
Fortunately Norton Power Eraser doesn't wipe the "threats" it detects automatically, so this isn't necessarily a bad thing. If you're sure a program is safe, then leave it; if it picks up something you don't recognise or entirely trust, then click the Fix button and it'll be removed. There's always the option to undo this later, if it proves to be a mistake.
Still, Norton Power Eraser is a program to be treated with care. Only use it when you have strong reason to suspect a malware infection, and all your other antivirus tools have failed. And even then, don't automatically delete everything on its list of detected threats - check carefully before you click the Fix button.