I have a Ubuntu 8.04.1 LTS DVD. But i could not able to install. It does not boot. please tell me how to install it.

You really need to be able to boot from the DVD or CD first, before you install Ubuntu. It sounds like the DVD isn't set up to be bootable. When you browse the disk, what do you see on it? Do you see files such as autorun.inf, md5sum.txt, and wubi.exe, along with half a dozen directories, including "boot", "casper", and "ubunt"? If instead you see "ubuntu-8.04-desktop-i386.iso", then the startup file image wasn't properly burned onto the disk.

The other possibility is just that you simply have a defective disk.

You really need to be able to boot from the DVD or CD first, before you install Ubuntu. It sounds like the DVD isn't set up to be bootable. When you browse the disk, what do you see on it? Do you see files such as autorun.inf, md5sum.txt, and wubi.exe, along with half a dozen directories, including "boot", "casper", and "ubunt"? If instead you see "ubuntu-8.04-desktop-i386.iso", then the startup file image wasn't properly burned onto the disk.

The other possibility is just that you simply have a defective disk. Also - this has fooled me before, though it seems obvious - you're not trying to read a DVD in a old CD-only drive, are you?

In addition to asure you've burned the image correctly you should consider to use the 10.04 LTS-version due it's longer life time.

Please verify the md5sum of your CD
     https://help.ubuntu.com/community/HowToMD5SUM

Sorry about the double-post above. I thought I'd stopped the sending of the first one before it reached its destination. Also, apologies for dumb afterthought added to the second post - obviously, if you're browsing the disk, it's not in the wrong kind of driver.