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anyone who's used Windows especially older versions is probably familiar with

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the dreaded dll error when you're in the middle of trying to do something

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although dll files seem to be important given how much Windows complains when

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one is broken or missing it's not exactly obvious what they are so let's

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explain why they're a big deal dll stands for dynamic link library but

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don't mistake them for a collection of zelda nfts the reason they're called

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libraries is that dlls contain shared code that multiple programs can link to

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and use kind of like how real libraries contain shared books that many people

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can borrow but dlls have an important feature that

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books don't several programs can use one dll at the same time and once a dll is

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loaded into a certain space in memory any program that needs the code inside

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can request access to that memory space without the dll having to be loaded over

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and over again a good simple example of this is this

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dll file which contains the code for bringing up a Windows popup dialog box

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since so many programs use this functionality it makes sense for this

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code to be included in Windows as a dll instead of writing it into every program

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from scratch another good example is the device driver which is the code that

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allows Windows and other programs to communicate properly with hardware

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drivers often take the form of dlls though they can appear as dot sys files

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in Windows explorer which allows multiple applications to access your GPU

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keyboard or printer its drivers at a

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time and because dlls are only loaded up when a program specifically asks for

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them instead of every time the program starts they also prevent your RAM from

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filling up with tons of unnecessary code this modularity means that new

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functionality such as game updates or support for different languages can be

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added to older programs simply by writing new dlls rather than having to

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modify the program itself that's not only more convenient but you don't run

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the risk of inadvertently breaking the code of the main executable but if dlls

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are such a good idea why are they so notorious for creating problems often

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referred to as dll hell we'll tell you right after we thank

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required at freshbooks.com techquickie so one big reason dlls cause

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problems is that when an application depends on lots of dlls it also means

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that application has many possible points of failure if a dll gets modified

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there's no way for a program that loads up the dll to ensure that the new code

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is compatible and if it isn't the program you want will often simply crash

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you see some programs will go messing around with dlls in a way that they

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shouldn't an installer for example may decide to modify a dll in a way that

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helps that specific application but can cause errors in the possibly many other

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programs that need the same dll but aren't compatible with the modified

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version for a long time microsoft expected third-party software developers to

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verify that any dlls they installed especially if they overrode existing

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ones would comply with accepted standards but needless to say with

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developers typically more concerned about making sure their own software

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works it often simply didn't happen and programs kept installing troublesome

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dlls with impunity mercifully this problem has been mitigated to a large

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extent in more recent versions of Windows microsoft has locked down system

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dlls so that third-party applications can't mess with them unless they've

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actually been authorized by microsoft itself Windows can now also track dll

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installations to try to prevent unknown dlls from making their way onto the

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system as well as to allow two different versions of a dll to exist

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simultaneously to prevent programs that rely on an older revision from breaking

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when you add a new one and with modern pcs having a lot more memory than the

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computers of the 90s and early 2000s the memory limitations that necessitated

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dlls in the past aren't as prevalent today meaning that modern programs often

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don't rely on dlls nearly as much maybe stuffing 64 gigs of RAM in your

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personal rig wasn't such a big mistake after all but you know what is a mistake

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not liking this video and subscribing so do it