To remove the multiple operating system screen choice window on startup.

1.	Right Click on Start then left click on Explore.
2.	Tools-Folder Options
3.	Click on Show hidden files...
4.	Uncheck the box “Hide protected operating system files”
5.	In the root C: directory double click on the boot.ini file

This is what a single boot boot.ini file looks like

[boot loader]
timeout=30
default=multi(0)disk(0)rdisk(0)partition(1)\WINDOWS
[operating systems]
multi(0)disk(0)rdisk(0)partition(1)\WINDOWS="Microsoft Windows XP Home Edition" /noexecute=optin /fastdetect

You might make a backup copy of the original boot file in case something goes wrong.

Before exiting make sure you re-activate the “Hide protected operating system files”

Also hide hidden files....

Save and Reboot.

Works like a charm.....