Service pack 3 setup cannot update...Error

At times for some, if you have tried to install XP SP3, after extraction of files, you might have received this error -

Service pack 3 setup cannot update a checked (debug) system with a free (retail) version of Service Pack 3, or vice versa



The reason behind this problem is...

multiple builds exist,each of which require their own version of the update.Follow these simple steps and your problem should be solved. You would need to use the registry editor for this -

• Click ‘Start | Run...’ and Type ‘regedit’ and press [Enter].
• Then go to ‘HKEY_LOCAL_MACHINE\Software\Microsoft\Windows NT\CurrentVersion’
• In the toolbar on the right, look for a string value "CurrentType". Change its value to ‘checked’. If it is already set to ‘checked’, then set it to ‘Free’ and click
• on ‘OK’.
• Exit the registry editor and try to install Service Pack 3 again. Now it should install without any problems.

Ref: Chip