DLL stands for Dynamic Link Library - they're files that perform certain processes. Your modem, for example, will have a DLL file that performs certain modem-related processes - any program that uses your modem will run these processes through the DLL, so if one is missing then you can get into all sorts of problems. Often these files will be updated regularly (by the modem manufacturer in this example) to work more efficiently, fix any bugs in previous versions and work with more recent operating systems.
The first step in restoring any missing DLLs is to find out what it is that is missing - you'll normally get a dialogue box come up that tells you if one is missing - stick the file name into Google and you should be able to find out what it is. If it is a modem DLL then you should be able to restore this by digging out a CD or floppy that came with your modem and reinstalling it. Or, you could go to the manufacturer's web site and see if they have the most recent DLL files available for download. Or, you could search one of the many DLL sites that exist for a copy. It's most likely that the manufacturer will have the most recent version so I'd try that first.
Hope this helps.
― Alfie (Alfie), Tuesday, 8 October 2002 21:03 (twenty-three years ago)