[Boot Win by default] 64 Bit 10.04 dual boot

You first need to determine what version of GRUB you are using. If the file "/boot/grub/grub.cfg" exists, you are using GRUB 2. Otherwise there will be a file "/boot/grub/menulst". This old file may still exist on your system. If you are using GRUB 2, follow instructions located at http://ubuntuforums.org/showthread.php?t=1195275. If you are using GRUB 1, follow directions at http://www.linuxquestions.org/questions/linux-software-2/changing-default-os-in-grub2-765011/. I hop this helps.
Joe

You can easily change your default os in System>Administration>Startup Manager.

i did not find that, under admin...

You never said what version of Ubuntu you are running. Open Synaptic Package Manager(System->Administration->Synaptic Package Manager. Search for "startupmanager" and make sure it is installed. If not, install it,and it should appear under System->Administartion->Startup-Manager.

Sorry, you mentioned the Ubuntu v\ersion in title.

Solution proposed by Joe has a drawback. At each new kernel delivery, Windows will be put again in last position.
In folder /etc/grub.d (not sure of path), you will find a file named 30_osprober.
Make a backup of file /boot/grub/grub.cfg
Rename this file, and replace "30" by "15".
Then run command
   sudo update-grub
Check in /boot/grub/grub.cfg that now Windows is before Linux kernels.
Then reboot.
This change will be permanent.

I give these data from memory, if there is any problem, post again and I will check at home on my PC.

can you check on your computer for the path? i am new to ubuntu so i am not that familiar with the command line and where that folder /etc/ is under home folder? can u please be as detail as posible.thank you. @joe thanks for the info

Hello,
If your issue is closed, please mark question solved.
Else I should have some time next week to help you.

sorry computer crash and need need Hard drive... have to wait to next friday to be deliver.

Thanks delance, that solved my question.