I can not install win millenium aldough I use start up disk or cd provided from manufacturer.Why?

Please provide as much information as possible since we can't see your computer.

What happpens when you try to install it?

Make sure that you change the boot order in the Bios so that it boots from CD. Since i dont know what kind of computer you have, i will give you the most common keys. When the computer first starts up tap these repeatedly to get into the bios: Delete, F2, F11, F5, F9. When you have done that, go to boot sequence or bios options --> boot sequence and have it read from the CD Drive first. Hit the save key and choose to save and exit. Reboot your computer with the disc in the drive. If the computer asks you to press a key to boot from a CD, do so. If this does not work make sure that you actually have the correct restore cd.

Cheers.