[badass]

A .DLL is a very small but a very important file (direct link libary) it will link your program to something on your pc to make that particular program work (you do not say what it is you are trying to run) useually reinstalling the program replaces the offending .DLL
If you have windows 98 you can fix corrupted files by going to sytem information (click on START, PROGRAMS, ACCESORIES,SYSTEM TOOLS) When the sytem information box appears click on tools and select system file checker and scan for altered files. Its worked for me EASY. If you ever get the option to keep a .DLL when you are deleting something KEEP IT it saves a lot of grief later believe me