Discusses an issue with installing or upgrading Windows XP on computers that run earlier versions of Windows. During the upgrade or the installation, you receive an "NTLDR is missing" error message.

Discusses an issue where you cannot start your computer after you modify permissions in Windows 2000, Windows Server 2003, or Windows XP. Provides step-by-step resolutions for this issue.

When you upgrade from Microsoft Windows 95 or Microsoft Windows 98 to either of the operating systems listed at the beginning of this article, you may receive an error message similar to the following during the first restart: NTLDR is missing or...