GMail Icon Setup
UPDATE: Now Truly Make Gmail Your Default Email Client!
Click Here For the Gmail Icon Notifier, A full integration of Gmail into the Windows OS

Here is a little installer I put together with NSIS. It simply adds the registration keys needed to set GMail as the default email application in windows. And places the GMail icon on your system.
It does not grab the mailto links. For that I suggest you use Google's GMail Notifier.
How does it work? What does it do? Well it's pretty simple. It simply adds the following keys to the registry.
[HKEY_LOCAL_MACHINE\SOFTWARE\Clients\Mail\Google GMail] @="Google GMail" [HKEY_LOCAL_MACHINE\SOFTWARE\Clients\Mail\Google GMail\DefaultIcon] @="C:\Program Files\GMail Icon\GMail.ico" [HKEY_LOCAL_MACHINE\SOFTWARE\Clients\Mail\Google GMail\shell] [HKEY_LOCAL_MACHINE\SOFTWARE\Clients\Mail\Google GMail\shell\open] [HKEY_LOCAL_MACHINE\SOFTWARE\Clients\Mail\Google GMail\shell\open\command] @="rundll32.exe url.dll,FileProtocolHandler http://www.gmail.com" [HKEY_CURRENT_USER\Software\Clients\mail] @="Google GMail"
It also adds the GMail Icon to the default install folder on your computer.
I have also tested the uninstaller it completely removed the program and sets the default email to nothing... so you can re-choose the default email client you want to use.
It also works in Vista!!