What is DLL Hell?

 Posted by Bharathi Cherukuri on 2/8/2012 | Category: ASP.NET Interview questions | Views: 26927 | Points: 40

DLL Hell:

DLL Hell refers to the set of problems while sharing multiple applications under a single common component like Dynamic Link Library(DLL) or a Component Object Model(COM) class.
Simply, it is the problem which occurs while registering the DLL components with a common name.
DOT Net has removed this problem by introducing the concept of versioning.


Versioning is a process where, every shared application creates its own version number.

For Example, Let us assume that the version number of the first registered DLL takes as V1.0.
And Now, you want to overwrite the first registered DLL by installing another DLL with same name.
Then the version number of the second registered DLL would be taken as V2.0.

By this way we can avoid the conflicts of DLL registration and can overwrite the registered DLLs successfully.

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Comments or Responses

Posted by: Chvrsri on: 2/9/2012 | Points: 10
Yes good question. When we work on a VB6.0 component then we can understand the importance of this concept. Soon after every small modification made in the code we need to manually make the dll and make the "IISRESET" once only then the changes gets affected.

When we want to add a new version of our project we need to replace the dll's by unregisterring the present dll's and copy the new dll's and register again.

Unlike in .Net we need not do all these changes as the DLL hell problem has been resolved here.

Nice post !!!
Posted by: Bharathi Cherukuri on: 2/10/2012 | Points: 10
Hi Chvrsri,

Nice explanation !!!

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