Editing DLL hell (section)

===Incorrect COM registration===
In [[Component Object Model|COM]] and other parts of Windows, prior to the introduction of [[Side-by-side assembly|side-by-side]] registry-free assemblies,<ref>{{cite web |url=http://msdn.microsoft.com/en-us/library/ms973913.aspx |title=Registration-Free Activation of COM Components: A Walkthrough |publisher=[[Microsoft]] |author1=Leslie Muller |author2=Steve White |date=July 2005}}</ref> the [[Windows Registry|Registry]] was used for determining which underlying DLL to use. If a different version of a module was registered, this DLL would be loaded instead of the expected one. This scenario could be caused by conflicting installations that register different versions of the same libraries, in which case the last installation would prevail.