Delete ubuntu without any cd

You don't need a Windows CD to delete Ubuntu. I'm assuming you are asking how to remove Ubuntu and reinstall Windows. You probably also don't have a dual-boot set-up or you wouldn't have mentioned the Windows CD. So do you have a pen drive or a blank DVD? How did you install Ubuntu? You can burn a copy of Windows on a flash drive in place of a CD. There are many tutorials out there. You will also need to delete the GRUB bootloader.

How did you install Ubuntu? Did you use Wubi, or did you resize NTFS and install to its own partition

Without knowing this, we cannot advise. The question is too vague.

actionparsnip has right. If we don't know how you installed Ubuntu , there is a possibility that you will cannot boot at all.

Is this a wubi.exe installation of a regular dual-boot from Ubuntu CD/DVD ?

Thanks

Put simply if have Ubuntu as the only OS then Windows is not there any more and you will need a legal Windows CD to install windows or another Linux distribution if you want a different Linux. Unless your computer has a recovery partition. Some do, particularly laptops, if which case there may be an option to restore factory defaults in the BIOS providing the recovery partition has not been overwritten.

If you installed with Wubi you can boot into windows and remove Ubuntu from add and remove programs.

If its a dual boot then you can also get rid of Ubuntu without a CD. Its a little more complicated as you no longer have the windows boot loader so you need to keep Grub.

Let us know what's installed and how so we can advise further.