How to change from grub boot loader to windows boot loader

Hi,

I had a dual boot system with windows 7 and ubuntu 12.04 LTS. Unfortunately ubuntu 12.04 had crashed but the grub boot loader remains. Ubuntu is not recoverable at present.
Presently I am able to boot into the windows 7 through grub. Now I want to use ubuntu inside windows 7 (Virtual Machine).

Now my question is:-
Can I change the boot loader from grub to windows boot loader (Without disturbing the existing windows 7)?
(then I will be able to delete the partition where the earlier ubuntu was loaded.)

If is there any way, yours comments and suggestions will be highly appreciable.
Thanks.

BNZ