Find the location of aximp.exe (on my computer, it was at C:\Program Files (x86)\Microsoft SDKs\Windows\v7.0A\Bin)
At an elevated command prompt, navigate to the aximp location and execute the following command: aximp %WINDIR%\system32\shdocvw.dll
This will generate SHDocVw.dll and AxSHDocVw.dll in the respective location... you can now add a reference to these files and access the proper control within C#.
To actually utilize the axwebbrowser... customize the toolbox and enable a COM Component for the "Microsoft Web Browser". This will allow you to add the AxWebBrowser control (shows up in the toolbox as "Microsoft Web Browser").
reference: where can I download AxSHDocVw.dll ?