signature error

[Betty]

I can,t use IE because of this error, which came up from
nowhere!!! Internet explorer--error signature
AppName: iexplore exe. Mod Ver: 6.0.8665.0
Offset: 005bf55
AppVer 6.0.2600.0 Mod Names: Mfc42.dll

I have been told it is an adware application that needs to
be deleted to I should do a disk cleanup.The ERROR keeps
cropping up whtn I click on IE. HELP HELP!!!