how to remove debian from my dual boot pc and replace it with ubantu
 

i am quite new to linux few months back i loaded debian in my desktop pc with windows xp. now i want to replace debian from my dual boot pc with ubantu while retaining windows xp. i don't have an xp boot cd.

boot Xp and run fixmbr or fdisk /MBR, whatever the windows method of the era was for restoring the windows bootloader. Otherwise installing ubuntu should be much like installing debian was, it will overwrite your debian install. Which will mess up the bootloader for debian until such time as the bootloader for ubuntu gets installed. Restoring the windows bootloader gives you the option to reboot to xp while in progress in case you only have the one machine.

You can just boot to the ubuntu cd, open gparted, then install ubuntu to free space.
There is no reason to run fixmbr, because Ubuntu will recognize the windows installation & add it to grub

Yes, just install Ubuntu (based on Debian only controlled by more people*) and in the procedure wipe the Debian partitions replacing with Ubuntu and a new bootloader it will detect microcoughed as-well. :confused:

Put the Ubuntu CD into your drive and simply install Ubuntu over Debian. Doing thos will wipe Debian off the drive by formating the partition it's on and then install Ubuntu on the clean partition. If you do it any other way you are adding to the process and not getting anything extra out of it.

replacing debian with ubuntu
 

If your worried about corrupting your MBR you can back it up with the dd command.