A DLL (dynamic link library) is a small program that is used for a specific purpose by the main program that calls it. Windows programs like Word and Excel call and use many DLL files.

Unlike most programs, that link and compile all the program elements they need before they begin executing, DLLs are only loaded and used as they are needed. This feature saves RAM space, which is a valuable resource. A DLL file usually has a filetype of '.dll'.

For example, when Microsoft Word is editing a document, the printer DLL file is not loaded into RAM. If the user decides to print the document, only then does Word load the printer DLL file.

Don't ever erase a DLL file unless you are positive it isn't needed by your PC. Erasing an important DLL file can make your PC inoperative until the file is replaced!

If you don't have a DLL you need, your operating system should display which one(s) it can't find, In that case you may be able to find and download them Click here

Drivers

A driver is a special type of software. Whenever your PC needs to connect to and control a peripheral device like a printer or scanner the driver written to work with it is required.

The level of the driver needs to be matched to the level of the device it is controlling. Some drivers are backward compatible. HP has done a good job with its PCL (printer control language) by making each successive PCL version backward compatible with earlier versions of printers. This can save a lot of headaches for you.

If you lose a driver or have the wrong one installed your peripheral device becomes a 10 pound paper weight.

So what do you do if you need a driver? Try going to the hardware manufactures website and looking for a link to drivers. You may have to click around a lot to get to the right spot depending on teh organization of the web pages. Once you do you'll need to enter the model of the hardware you seeking the driver for. Then you can download and install it following the instruction that come with it.
If you can't find the driver you need http://www.drivershq.com/