Go to Control Panel, System, Advanced, Startup and Recovery, Settings. In
the System Startup secction click Edit.
A typical BOOT.INI file for a single hard disk, single partition, single
operating system looks like this:
[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
Professional" /fastdetect
If the above does not match the description of your computer, post back with
more details.