This is a logon screen for Stardock's Logon Studio. Basically, it changes your regular logon screen for Windows 7/Vista to the wallpaper seen in the Sherlock theme.
Stardock Logon Studio can be downloaded here: [link]
WinRar can be downloaded from here: [link]
1. Download and install Logon Studio and WinRar from the provided links.
2. After WinRar is installed, right click the file you downloaded from here and choose "Extract here."
3. Open Logon Studio.
4. Click the "load" button, and select the file that you extracted.
5. After it's added to your logon screens, click it, press "Apply", then press "Save".
6. Enjoy your new logon screen!
If you need help or have questions, just comment below.