File Cleanup

Is it typically safe to delete all *.bak, *.tmp and *.old files? Normally, I would think so. But when I see large files like the following, I start to wonder a little -- and get a little nervous:

c:\windows\system32\config\software.bak

c:\windows\system32\config\system.bak

c:\documents and Settings\user name\NTUSER.bak

c:\1386\shdocvw.bak

c:\windows\system32\shdocvw.bak

And the list goes on . . . over 175 "unnecessary files." Some of these files are very large, but list contains smaller ones as well. I would love to do some cleanup work, but don't want to make any stupid mistakes along the way.

These are from using a registry compacter/optimizer program like NTREGOPT, or from a restored registry backup using ERUNT, and it's safe to remove them:

c:\windows\system32\config\software.bak

c:\windows\system32\config\system.bak

c:\documents and Settings\user name\NTUSER.bak

These I don't know about (edit: but most .bak extension files can safely be removed):

c:\1386\shdocvw.bak

c:\windows\system32\shdocvw.bak

These are from using a registry compacter/optimizer program like NTREGOPT, or from a restored registry backup using ERUNT, and it's safe to remove them:

These I don't know about (edit: but most .bak extension files can safely be removed):

c:\1386\shdocvw.bak

c:\windows\system32\shdocvw.bak

You are right, I do use the ERUNT apps. These aren't the actual ERUNT registry backup files that are created when you do a registry backup, are they? I mean the ones that would be used to restore the registry should that be needed? I assume these might be some sort of secondary backup files.