Each Windows OS has its own build number which is shown in its Beta builds but not shown in RTM versions. This build number on Desktop is also called Watermark. For example, Windows Vista SP1 shows its build number as "Build 6001" on Desktop.

In this tutorial, we'll change this build number to our custom string and will show that custom string on Desktop. You can put your name, your website URL or anything which you want to show.

It might also become very useful to customization pack creators who can show their customized text like any beta build number or their pack version/name on Desktop.

So here we start our tutorial:

1. First thing is to enable "Build Number" on Desktop. There is a simple registry trick to show it.

Type regedit in RUN or Start Menu Search box and press Enter. It'll open Registry Editor. Now go to following key:

HKEY_CURRENT_USER\Control Panel\Desktop

In right-side pane, change value of "PaintDesktopVersion" DWORD to 1 (Create the DWORD value if its not present).

2. Now log off or restart your system and you'll see the Build number on Desktop:

3. We have completed first step. Now we have to customize this Build number. For this task we'll need to edit a system file "%windir%\System32\en-US\user32.dll.mui" in Resource Hacker.

NOTE: Here %windir% represents "Windows" directory which can be found in the system drive where Windows is installed. In most of the cases its C:\Windows. And if your Windows language is different, then replace en-US in the above path with your language code.

4. Now copy user32.dll.mui file from "en-US" folder to some other location for example Desktop and open the new file in Resource Hacker.

5. Once you open the file, go to "String Table -> 45". In right-side pane, look at the 715 and716 entries. The 715 entry contains the first line of Build number i.e. "Windows Vista (TM)" and the 716 entry contains the second line i.e. "Build 6001".

6. We need to change their text so that we can show our own desired text. That's very simple. Simply delete the text within double-quotes "" and type your own desired text in both entries as shown in following screenshot:

After changing the text, click on "Compile Script" button.

7. That's it. After modifying the string, save the file.

8. Now we'll need to replace original user32.dll.mui file present in "C:\Windows\System32\en-US" folder with our new user32.dll.mui file which we saved at Desktop or some other location.

8 a. First take ownership of "C:\Windows\System32\en-US\user32.dll.mui" file using following tutorial:

Add Take Ownership Option in File / Folder Context Menu in Windows

8 b. Now rename it to "user32_backup.dll.mui" or any other name.

8 c. Now copy your new modified "user32.dll.mui" file from Desktop to "System32\en-US" folder.

9. Restart your system and after restart Windows will start using your new modified file and your desired text will be displayed on Desktop:

PS: Please be very careful while editing any file in Resource Hacker. Changing Build number is completely safe and it'll not cause any problem.