The Windows XP Build number can usually appear in the bottom right hand corner of your screen and usually takes the form of 'Windows XP Build 2600' or something similar. In most cases, assuming you have a legal copy of XP, you will never ever see it. You may see it if you have a beta or evaluation copy of the software. But it has been known to mysteriously appear even on retail versions of the software. To remove it you need to edit the registry as follows:
The Registry is an important part of your software/pc, incorrect editing can cause problems on your machine. Therefore it is wise to backup your registry before attempting any alterations. Third party software such as Erunt are ideal for backing up the registry.
1/ Click the Start button.
2/ From the Start Menu click Run.
3/ In the Run dialog box type: regedit.
4/ The registry editor will now open.
5/ Now navigate to the following registry key: HKEY_CURRENT_USER\Control Panel\Desktop
6/ In the Right Hand Pane of the registry window scroll down the list until you come to PaintDesktopVersion
7/ Double click on the PaintDesktopVersion option.
8/ The Edit DWORD Value dialog box appears.
9/ In the Value Data box type 0 (zero) and click OK.
10/ Finally close the registry editor.
11/ The next time you boot up your pc the build number should have disappeared.
http://xphelpandsupport.mvps.org/how_do_i_remove_the_windows_xp_b.htmTags: Remove Windows XP Build Number From Desktop