If you believe you will be able to manage it then download a free Hex Editor, install it and open the DLL file with this program.
Generally DLL files don't get infected and the infected files contain the very body of the viruses.
Please tell us more about that DLL file, its name, its location and the virus that infected it.
Post Edited (Petria) : 6/1/2004 12:06:46 AM GMT