The simple way to modify the time-out is to open Control Panel > System. Then click on the 'Startup/Shutdown' tab and change the value of 'Show list for'. Any value between 1-999 is valid, if you choose '0' the system will wait forever for you to make a selection.
If you would like to boot Windows without waiting for the time-out the process is slightly more difficult.
Using Windows explorer find the file called BOOT.INI on your system drive. Make the file writeable, by right clicking on it and choosing Properties, and then under Attributes, uncheck 'Read-only' and click OK. Now double-click on BOOT.INI, and it should open in Notepad.
There is a line under the [boot loader] section labeled timeout=. The number after the '=' sign is the time in seconds Windows will wait for a selection. To make Windows boot instantly change this value to '-1' (i.e. timeout=-1). Save the file, and the next time you reboot Windows NT won't wait for a selection and just load the default OS choice.
