Norton Power Eraser & autochk.exe

A few days ago I was getting an error message when starting up my computer (APS Daemon.exe Bad Image).  It said it was somehow connected to C:\Program Files\Common Files\Apple\Apple Application Support\AppleVersions.dll)  So, I uninstalled all Apple products and ran Norton Power Eraser.  It identified autochk.exe as Bad but couldn't remove it.  I downloaded Spybot Search & Destroy to see if that could help.  It did locate around 40 issues and fixed them.  Then I re-ran Norton Power Eraser and it still said that autochk.exe was bad, and also now said that instb32.sys (both file and service) was bad as well.  It allowed me to "fix" the instb32.sys problem but the issue was only "resolved" until I restarted the computer.  Additionally, while the start up APS Daemon message no longer was appearing, my IE stopped working and things weren't running as normal. 

 

I was going to try to use a Vista OS disc to repair the issue, but found that I only had my Lenovo start and recovery discs which only allowed me to do a whole system recovery.  I did this and after getting all the Vista OS updates and Norton 360 updates, I decided to download and recheck with Norton Power Eraser to see if the recovery really got rid of all problems before putting any other documents/programs on the pc.  But NPE still comes back telling me that autochk.exe is bad.  (No mention of instb32.sys anymore though.)

 

How do I know if this is some virus/problem that needs to be fixed or simply NPE identifying something harmless as bad?