Why not to download DLL files ?

[Faakhir]

DLL download sites provides easy access to DLL files and also fixes for DLL problems by allowing single DLL downloads....but recently I have heard not to use DLL sites and not to download DLL files. WHY? What's the reason ?

[Spyrus]

Very important reason - DLL Download Sites are Not Approved Sources for DLL Files

DLL files are created and distributed by companies that develop software. Sometimes that software company is Microsoft, sometimes it is not. Many companies create DLL files as part of their software packages.

A stable, clean, and updated copy of any DLL file can only be guaranteed by the developer. Websites that allow individual DLL downloads are in all but the rarest cases not approved places for downloading DLLs.

Downloading a single DLL(from unauthorised source) file can cause a big trouble.
DLL files are only small parts of entire software programs. Often times, an error message that singles out an individual DLL file is only telling you part of the story. The particular error is often being generated only because it's the first problem the software is encountering, not because it's the single cause of the problem.

When you download and replace a DLL file from a DLL download site, you're often only solving one small part of a larger problem. Usually, the solution to the larger problem is to reinstall the entire software package that the DLL originated from.

Even if replacing a single DLL file fixes your immediate issue, additional problems tend to show up later, often as error messages notifying you of yet another missing DLL file. Save yourself a lot of time and energy and fix the problem right the first time.

[Snake08]

The biggest risk of downloading DLL files from DLL download sites is that they may be Infected with Viruses.
Since DLL download sites are not approved sources for DLL files and often have little if any contact information available, there is no guarantee that the DLL file you just downloaded is free from a virus infection.
Assuming you have a good antivirus program, an infected DLL file might be quarantined as you download it but there is certainly no guarantee of that.
Take the safe route and simply avoid downloading DLL files from these DLL download sites.

[Zachary]

Your Computer's Security would be highly at risk since DLL Download Sites Could Host DLL Files.

DLL files are like small, specialized programs that can be programmed to perform various actions automatically, even actions that open your computer up to hacking and other kinds of intrusions. DLL files like this do exist. While it's unlikely that you will search for one of these particular DLLs files to download and install, it is a risk you take when you install a DLL file in your system from a DLL download site.
Why to compromise system's security through unnecessary downloads ?