DLL Files 102 – DLL File Fundamentals, Part II
What is the Difference Between DLL Files and Windows Registry Files?
As mentioned in Part I of this two-part primer on DLL File Fundamentals (DLL Files 101), DLL files are stored in the Windows Registry. They do not, however, comprise the entirety of the contents of a Windows Registry. There are many more types of entries contained in the Windows Registry besides DLL files, such as:
• Startup Programs
• COM Objects
• Shared Folders
• Help Files
• File Extensions
Why DLL Files Exist?
In a word: efficiency.
Programs generally perform an untold multitude of tasks, most of which are never seen or otherwise noticed by the end-user (you and me). Beneath the surface of the primary tasks you use any program to perform (ie. build a spreadsheet with Microsoft Excel or edit a picture in Photoshop) are scores of other supporting functions that would be a waste of valuable time, effort, and space were a programmer to attempt to incorporate each and every one of them into the programs they develop.
Not only that, but doing so could potentially cause great confusion within a PC as several programs would be performing the same functions but in a slightly varying manner, almost certainly causing inconsistencies to arise
For example, if memory and hardware resources weren’t centrally controlled by DLL files, then all of the programs attempting to run at once might not get their appropriate and necessary share in order to function properly. Multiple programs attempting to run at the same time would end up competing for the same resources, causing confusion that could lead to errors and other PC performance problems.
Why Is Understanding DLL Files So Important?
After a PC is used for a period of several weeks or months, it is likely to become congested with an abundance of DLL files it doesn’t need. Frequently the system will copy a DLL file from one folder to another or install two or more versions of the same DLL file into different folders (if, for example, more than one program being installed includes in its directory the same DLL file).
Sometimes the program that used a particular DLL file is deleted or uninstalled or simply sitting idle, no longer used. In all of these cases, said DLL file will likely remain on the hard disk, also unused, merely taking up space and potentially creating unnecessary confusion for the system.
Still other times, a DLL file installed by a particular program is merely a duplicated of a standard DLL file already inherent in the system, maybe under a different name, maybe under the same name.
When DLL files are modified or deleted or become corrupted in any way, the Windows Registry reflects these changes. Traces of the modified, erased, or corrupted DLL file will almost invariable leave traces behind in the Window Registry. This ends up affecting how well (or poorly) other programs may run.