Couple of days ago my colleague Robert showed me a neat trick how to change login background in Windows 7 RTM. This feature was probably aimed at OEM builders to customize login screen although it has some interesting applications in other situations. For now, I am using it to amuse my wife. 🙂
So, how to do it. First of all, you will need to check one registry key. Check HKLM\Software\Microsoft\Windows\CurrentVersion\
Authentication\LogonUI\Background and if there is no OEMBackround entry, create one that is DWORD type and give it value 0 to turn off background image and value 1 to turn on background image.
Now that we enabled Windows 7 login background we have to create one.
I found one nice picture for my background but the problem was my screen resolution. When I changed size of the picture to fit to screen resolution, picture was out of proportions and looked really bad. Here is an example, bear in mind that my screen resolution is 1280 * 800.
You can see that the picture is unnaturally stretched on the left. Since I am not graphics designer and I am not master of Photoshop I had to use tools that where available to me. Here comes great free application, Paint .NET.
Here are quick steps on how to create perfect background for your login screen. Open Paint .NET and open your picture in it. On the left side, from the toolbar select Rectangle Select tool, then on the top bar where it says Normal, click on little arrow right of it and select Fixed size option. Now you can type in your own size. First, change inches to pixels and then enter desired size. Draw a rectangle on the picture and it will be exact size that you entered earlier. When you are happy with selection, click on the Crop To Selection button under Layers menu and that is it! Save your finished picture to C:\Windows\System32\oobe\info\backgrounds as backgroundDefault.jpg. The size of the picture can not be more than 256 kb. You can even control that just after you select Save for your picture. All pictures not fitting resolution will be automatically stretched. On the right you can see final result. No need to restart your computer. Just lock it (Win + L) and enjoy.