Many .NET developers know and love the .NET Reflector tool. If you are one of them, consider making Reflector the default action for when you double-click on (i.e., open) a .DLL file. Just like assigning Microsoft Word to open .DOC files, you can assign a program to open your .DLL files. It is easy… Here are the instructions for Windows 7 – for other versions of Windows the process is similar.

1. Download Reflector and install it; remember where it is installed

2. Using Windows Explorer, navigate to any DLL file on your computer

3. Right-click on the DLL and select “Open with…” from the popup menu

4. From the Caution dialog that appears, select “Open with…” (yes, you have to select it twice, once in step 3, again in step 4):

5. From the dialog that appears, choose the second option – “Select a program from a list of installed programs”:

6. Now you will simply need to choose  the “Browse…” button and navigate to wherever it is you installed Reflector.exe, click the “Open” button and you are done.

Now whenever you want to examine a DLL in Reflector, you can double-click on it from Windows Explorer. If you tool around in the command line like I sometimes will do, you can also launch the DLL in Reflector by just “running” it from the command line like you might do for a .txt document to open it in Notepad.

Realize that Reflector can’t do much with a DLL that is not actually a .NET Assembly, but will handle that case gracefully.