After you choose to start Windows from the Boot menu, you may experience a long delay (or pause) before your computer finishes starting. Note that this delay may range from 10 seconds to a minute. Also, this delay occurs before the Starting Windows progress bar appears, and your computer may appear to stop responding (hang) during this time.
This behavior can occur if Windows is installed on a drive or a partition to which Windows cannot gain access with normal Basic Input/Output System (BIOS) INT-13 or INT-13 extension calls. When Windows Setup determines it cannot use BIOS calls to start, it uses scsi() or signature() syntax in the Boot.ini file instead of multi() syntax.
For additional information about signature syntax, click the article number below to view the article in the Microsoft Knowledge Base:
227704 Windows 2000 May Use Signature() Syntax in the Boot.ini File
When booting a system that requires scsi() or signature() syntax, Ntldr loads an additional device driver (Ntbootdd.sys) to initialize and interrogate the boot controllers in your computer. Ntldr then seeks the associated boot drive attached to the controller to finish loading the kernel. These additional operations take more time in Windows because of the Plug and Play nature of the operating system.
This behavior is expected, however, Windows Setup may use scsi() or signature() syntax, even if your computer can boot using the normal BIOS calls. This may occur on Integrated Drive Electronics-based computers when using a large capacity boot drive. In this case, you can try adding an additional entry in the Boot.ini file and use multi() syntax on the new entry to boot from. Note that if this works, your computer starts without pausing.
For additional information about ARC names in the Boot.ini file, please see the following article in the Microsoft Knowledge Base:
102873 Boot.ini and ARC Path Naming Conventions and Usage
NOTE: The delay might still be present in Windows XP, but is not as noticeable and is reduced drastically to about 10 seconds or less.