Remove ubuntu

If you have installed it with WUBI, follow this:
https://wiki.ubuntu.com/WubiGuide#Uninstallation

If you have installed it on your HD like a normal system, follow this:
http://www.makeuseof.com/tag/how-to-safely-uninstall-ubuntu-in-windows-dual-boot-environment/

When i turn on my computer i dont get options in black and white,I get it the options in ubuntu
Like ubuntu 10.10
Recovery mode
previous versions !
Like that !

It sounds like you are stating you have the grub boot menu but no option to boot into windows or other OS (dual boot)

if this is the case you will want to install your other operating system (or boot into another live cd) and delete the Ubuntu partitions from there.

So I think you have removed the previous install of Windows. You should reinstall it.
Before do anything, do this:
1. Open a terminal by hitting CTRL + ALT + T
2. Insert and run this command:
sudo fdisk -l

3. It will ask for your password, just type it in and press enter, you will not see anything when you type in your password for security reasons.

4. Copy and paste here all the output of the terminal.

vishesh@vishesh-HP-Pavilion-dv5-Notebook-PC:~$ sudo fdisk -l
[sudo] password for vishesh:

Disk /dev/sda: 250.1 GB, 250059350016 bytes
255 heads, 63 sectors/track, 30401 cylinders, total 488397168 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x1776f019

   Device Boot Start End Blocks Id System
/dev/sda1 * 2048 102402047 51200000 7 HPFS/NTFS/exFAT
/dev/sda2 102402048 448483325 173040639 7 HPFS/NTFS/exFAT
/dev/sda3 448483326 488396799 19956737 5 Extended
/dev/sda5 482246656 488396799 3075072 82 Linux swap / Solaris
/dev/sda6 448483328 476094463 13805568 83 Linux
/dev/sda7 476096512 482238463 3070976 82 Linux swap / Solaris

Partition table entries are not in disk order

Try to restart, and after the bios screen and before the Ubuntu loads, press the SHIFT key repitely. You should see the OS installed on your system. Windows should be on this list.

repeatedly*

The factory installed os is windows vista

Have you it in the list? If yes, you can use it and remove Ubuntu by following this guide:
http://www.makeuseof.com/tag/how-to-safely-uninstall-ubuntu-in-windows-dual-boot-environment/

I am sorry but its not on the list !

So there aren't Windows on your HD, you should reinstall it.

take the backup of your essential data and then boot the PC with your recovery disk in the drive. it will automatically remove any existing OS and install your factory shipped vista provided you do have recovery disks. if not, load the disk of any OS you like and start the PC. go ahead with the installation.