I'm not really a big fan of GRUB (I had a bad experience), nor very knowledgeable about Linux, so how do I remove GRUB, and replace it with Windows NT Bootloader, yet keep the same list/number/entries of OS, but swap bootloader? I have installed Ubuntu 12.04 Alpha 2 after Windows.
You can use EasyBCD as shown in: Is it possible to boot Ubuntu using the Windows bootloader? But installing GRUB to a partition instead of the MBR is strongly discouraged as GRUB will tell you.
If you're using 2 or more hard drives and can set up the boot device order in the BIOS and/or choose the boot device at boot via F8 oer F12, I recommend installing every OS on a separate hard drive and the corresponding bootloader only to the corresponding MBR.
As I can imagine from your answer, it's not only GRUBs fault. Please use Linux tools like
Replacing a Ubuntu GRUB installation by a Debian GRUB installation, after resizing a Windows partition with a third party tool, trying various other workarounds, fixing the MBR with the Windows Rescue tools, doing other stuff that breaks Windows and putting the blame on "GRUB" can just be described as FUD and is the wrong way to go.
You probably shouldn't. At this point, I will indemnify myself by saying that you use the following information at your own risk and I have not tested it. Also, it may be out of date and not work with Grub 2.
I imagine you could do it with a combination of http://bkpavan.wordpress.com/2008/04/02/how-to-boot-linux-using-windows-bootloader-xp/ and http://kb.acronis.com/content/1507 - but we are talking super-advanced stuff. You run the risk of making your machine unbootable or worse.
The real question is: What did Grub do that you didn't want it to? With issues like this, the best mantra is if it ain't broke, don't fix it.
Since you claim to not be knowledgable of linux, and want something simple
The simplest and safest way get the functionality you are after is to install Ubuntu with WUBI
This will give you a boot option in your windows boot loader to boot into linux. ubuntu will be installed as an application in windows. To remove the entry from your windows boot loader just uninstall the program in add / remove programs