Next time you need help, it would save us a lot of time if you also included a link back to the where you read these instructions. On this forum, a lot of things get discussed about different things.
I assume you mention this:http://nu2.nu/bootcd/#cdromsi
5) When you're done customizing, you open a command prompt, change to the BCD folder and run "bcd cdromsi" to build your ISO image and burn it to your CD writer (if you have one).
You need to use the windows console.
- Click on the Start menu --> Run
- Type "cmd.exe"
- Then change dir inside the console until you reach the BCD folder (I recommend placing this folder somewhere like "c:\bootdisk")
- Type "bcd cdromsi" to run the program with the given parameters.
You need to know how to use the console, there are plenty of tutorials out there or perhaps you can ask a friend to teach you in person how to perform this operation. Really recommend to learn how to use it, very useful tool.