When an XP repair CD is used, it replaces all system files (including Windows Update) on your machine with older versions of those files and restores the registry," said Nate Clinton, program manager for Windows Update (WU), in a post to the Microsoft company blog dedicated to the update service. "However, the latest version of Windows Update includes 'wups2.dll' that was not originally present in Windows XP. Therefore, after the repair install of the OS, wups2.dll remains on the system, but its registry entries are missing. This mismatch causes updates to fail installation.
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