How to uninstall ubuntu 12.04 in dual boot windows

Did you install using wubi, or did you resize your NTFS and install to it's own partition?

I had 33 gb of unallocated space before installing ubuntu 12.04 from a cd. I had created a separate partition of 19 gb and installed it there. Now the remaining 14 gb has become unusable and i am not able to use it in any of the operating system.
I also had to extract 1 gb of space from my windows7 'E' drive for the swap area because of unusable 14 gb.

Try using this tool to see if the unusable space is there or not, if it is there and you cant use it, try re-partitioning it:
http://www.partition-tool.com/download.htm

I use it for my computer but i downloaded it a while ago, its always pulled through for me.

Hope it helps

But how to unistall 12.04????
please help me with dat....

It's 'that', not 'dat'. tryi using full english words. You aren't charged by the word here and it helps none-native English speakers.

If you load the Windows disk manager, you can delete the Ubuntu partition and format it to NTFS for data storage. You will need to reinstate the Windows boot loader as you will remove Grub.

oops...okay....sorry for using "dat"....What does "reinstate the windows boot loader" mean???

The drive currently is using Grub to boot. If you wipe out your Ubuntu partition, the data grub needs will be lost and not able to boot. You need to put the bootloader windows uses back on the MBR so that it boots windows.