How to remove alternate operating system from PC?

Ok I will assume u r running Windows 98 and Xp.
Start Windows Xp and right click on my computer and then got to properties.
Then go to advanced, then start up and recovery settings.
You will see the name of ur default OS, click on edit and remove the other OS.
JUST REMOVE THAT LINE NOTHING ELSE PLEASE BE CAREFUL!
Now click ok and save and exit that. Now u can format the drive of the other OS and that OS is completely removed.