windows loads automatically, cannot install

What release of Ubuntu...?
From which link have you downloaded on the cd...?
It was an .iso file ?
Have you burned it at lower speed you can do...?
Usually, can your pc start from other bootable cd...?
Have you checked the bios setting of your pc... to be sure it have as first boot device the cd-rom...?

Below some common suggestion and hints to solve install issue...

Some suggestion and tips to solve install issue...

- Minimum system requirements to install Ubuntu 8.04.1 https://help.ubuntu.com/community/Installation/SystemRequirements

Download the standard Ubuntu 8.04.1 32 bits iso image from here:
http://releases.ubuntu.com/releases/8.04.1/ubuntu-8.04.1-desktop-i386.iso
or better using a torrent file:
http://releases.ubuntu.com/releases/8.04.1/ubuntu-8.04.1-desktop-i386.iso.torrent

- Please check the md5sum of your downloaded Ubuntu .iso image file, here the https://help.ubuntu.com/community/HowToMD5SUM howto, and compare with http://releases.ubuntu.com/8.04.1/MD5SUMS

- Burn it on a cd rom, be sure to burn your cd at lower speed you can do usually 4x here an howto https://help.ubuntu.com/community/BurningIsoHowto

- Please also check the md5sum of your self burned cd. https://help.ubuntu.com/community/HowToMD5SUM

- Boot your pc from self-burned cdrom, if it don't start from cd please modify your pc BIOS settings by accessing to it usually pressing CANC or F2 or other keys (check into your motherboard paper documentation or watch carefully the screen, usually there are tips to access BIOS, when you switch your computer on)

- then to be sure your ram is ok, boot from Ubuntu live cd main menu and at first showed menu, select the item "Memory test" to test your pc ram memory

- Here the steps to install Ubuntu 8.04.1 https://help.ubuntu.com/community/GraphicalInstall

- Watch this video that show howto install Ubuntu on a pc with Windows: http://screencasts.ubuntu.com/Installing_Ubuntu_with_Windows_Dual-Boot

- if something go wrong at startup of Ubuntu live installation when you see the first cd menu like this http://i18.tinypic.com/6tzzndc.jpg pressing F6 you can put useful startup kernel boot parameters https://help.ubuntu.com/community/BootOptions as showed here

Try to perform the "Memory test" and the "Check cd for defects" to be sure the cd is read without errors by the destination pc cdrom driver

- Booting from Ubuntu live install cd:
 * if you are in trouble with screen graphic user interface
   (usually the screen is black with a blinking cursor or screen out of range message):
- first try to dynamically change screen resolution please the press CTRL + ALT + "+" and/or CTRL + ALT + "-"
- Try to restart the graphic layer press CTRL + ALT + BACKSPACE
- Here the basic step required during install process http://www.howtoforge.com/the-perfect-desktop-ubuntu-8.04-lts-hardy-heron

If you are still in trouble... please reboot your pc and starting with Ubuntu live cd please try to put some common Ubuntu kernel live cd options you can find the boot options howto here: https://help.ubuntu.com/community/BootOptions

Remove the "splash" and "quiet" options to see more boot infos message and/or errors.
Then try some commons parameters by putting them one by one or together:
noacpi nolapic nodma all_generic_ide

If this don't work i suggest you to download and burn on a cd at lower speed you can do (4x), here an howto https://help.ubuntu.com/community/BurningIsoHowto, the Ubuntu alternate install cd iso image ( ubuntu-8.04.1-alternate-i386.iso ) you can download this cd from here: http://releases.ubuntu.com/8.04.1/

If you are in trouble to download you can try to install and use a torrent client Deluge http://www.deluge-torrent.org/downloads.php to get your desired Ubuntu iso image http://releases.ubuntu.com/releases/8.04.1/ please select a .torrent file

*** if you are installing in dual boot mode Windows + Ubuntu

Please make sure you Windows partition have no errors on it.

Booting in Windows force an a complete hard disk check.
Then reboot again in Windows and make a clean shutdown.
Be sure to boot in Windows twice and to get a clear Windows shutdown.

***

Always useful is the online Ubuntu doc https://help.ubuntu.com/8.04/

Hope this helps

Many times it is just enough to press F11 just when you turn on your PC and then select the drive where ubuntu is. Tell us if this worked for you

Well? didi it work for you?