installation problem

I/O ERROR
ERROR READING BOOT CD

HOW WE CAN FIX THAT?

Hi There,

It's possible that the specs of your machine are not high enough to run the Graphical Install Client, either that or there is some underlying issue causing it to hang.

One suggestion I can make is you follow the alternate install CD method. This works on hardware that is either troublesome or not powerful enough to boot into the Live CD environment. There is a tutorial here. You will need to also download a different ISO file.
The ISO is listed here:
http://releases.ubuntu.com/feisty/

The ISO for a i386 PC is here (but you maye have a different architecture):
http://releases.ubuntu.com/feisty/ubuntu-7.04-alternate-i386.iso

And a Guide to help you is here:
https://help.ubuntu.com/7.04/installation-guide/i386/

If you are getting an IO Error then it is either an incorrectly downloaded image (you need to check the MD5sum to verify it is the same as hosted on the server) or there is burn error on your CD-R. It is worth burning at a slower speed.

It may also be possible there is a problem with the cable in your CD-Rom drive in the PC. Please check your cables and make sure they are all connected properly and there is no damage to them. If possible you should try another CD Drive if you are certain the CD was correctly burned and downloaded from the server initially.

And how we can fix that problem to help ubuntu
in the future? What i have to do? The I/O ERROR
ERROR READING BOOT CD

try https://help.ubuntu.com/community/Installation/CDIntegrityCheck