I think anyone would want to uninstall ubuntu for various reasons,and I uninstalled my ubuntu just ago.I will show you how to do it in this tutorial.
First,you need a program and download it just by clicking Download at the bottom of the page.
then,extract it and run BOOTITING.EXE
Type yes to continue and choose to make a bootable floppy or cd file
Press enter and at the next window will create BOOTITING.ISO
Now you can run makedisk.exe to burn it and restart your computer from the CD.
Don’t install it when you boot into the program,just cancel to run it off the cd,then go to the partition work and click oval at the left side of the window.Delete the partition for ubuntu,then there will be a free space and you can allocate it in Windows or select windows pration and click resize here.
Now you need to reset mbr because grub will crash when you restart and you will not go into Windows.
Select windows partion and click std mbr,then click apply.It will take grub off and set mbr back.
Restart the computer and you will go into windows as normal