How to find an item in "registry"

Hey, I'm having some problems with my computer, but others have used this method and has worked for them, but I don't actually know how to do it.

I was told that there Is a file in my registry "hkey_local_machine\software\microsoft\windows NT\currentversion\image file execution options\explorer.exe"
This Is what has stopped my comp from working properly... I was told it is found in the registry, but to me, that means nothing. Can someone explain step by step how I can delete this file please.