Somehow all my .DLL's are set to open with NOTEPAD.  What can I do to get them to open with the correct program?  What is the correct program?You should not open .DLL files at all. Windows will warn you that is a system file if you try to do so.use the restore function on your pc to rectify this problem..I didnt change them, someone else did.  I just need to know what is the correct program that is supposed to be associated with these files so that I can reset it.  you could try this c:\drive.../TOOLS /folder options/view....setup defaults..DONT know what folder options would do to reset the programs that open other programs.  I did as you requested, no progress.  File still opens with NOTEPAD.http://support.microsoft.com/default.aspx?scid=http://support.microsoft.com:80/support/kb/articles/q306/5/51.asp&NoWebContent=1I read your reply, visited that link, but it is asking me to choose an option under the Properities of the file that I wish to change.  I dont have the option to use the web to find the correct program.  I have a list of programs, and I can browse programs on my COMPUTER.  I found RUNDLL32 which should be the correct program to run DLL's, but when I apply the CHANGES to the file, it doesnt change from using NOTEPAD to open the .DLL's.I think the error is that the link you provided is troubleshooting for Windows XP.  I am on NT.