Take note that the Registry Editor is only the facade of the Windows Registry, and it is not the registry itself.Your computer will restart, but the bad news is that your previously unsaved data will be lost because programs did not get a chance to save it.Have you experienced an error popup which specifies on missing DLL files and pondered what really are DLL files? If at all you have tried opening the DLL file using Notepad that results in showcasing unreadable characters, then converting the code using a decompiler program shall benefit you more. The main job of a decompiler program is to revert the codes into a readable mode.
To open dll file, download a decompiler program that can let you see through the source codes that were earlier used to create the file for a particular program.