Repair Windows Vista MBR after Deleting Ubuntu from a Vista-Ubuntu Dual-Boot System

Description of the Problem

I was running a Lenovo T400 machine with dual-boot systems managed by grub. The machine came with Windows Vista pre-installed and Ubuntu was added side-by-side later. Since I found myself barely used Ubuntu recently for production work, I decided to get rid of it and create more free storage space. Then I did it after converting the Ubuntu system into a virtual machine (as a memory). The way I deleted Ubuntu from the physical machine was simply formatting the Ubuntu partitions (both the main OS partition and the swap partition) and merging them into a new partition, completely done in Computer Management of Windows. When Ubuntu was gone, so was grub. So, when I restarted the machine, expectedly, the system couldn't boot from the harddrive whose MBR was already modified by grub. I was facing the following prompts:

error: unknown filesystem.
Entering rescue mode...
grub rescue>

Well, clearly, I needed to repair the MBR of the harddrive where my Windows Vista still sat on. How to do this? Not being an expert, I GOOGLEd .... As this was already a well known problem to the community, I didn't search hard before reaching satisfying solutions. At least for me, two options were out there, 1) from bootable Windows Recover/Rescue/Installation CD (ref1, ref2) and 2) from a live Linux system (ref3). Honestly speaking, I didn't make a decision about which one to follow. I tried to follow both and see which eventually would work out with my current repair settings: a working Dell machine with Windows 7 but no CD/DVD ROM, two Windows 7 installation DVD's, some 2-16 GB USB flash drives, and nevertheless, the subject ThinkPad T400 with CD/DVD ROM. The final path I ended up succeeding was with a Windows 7 Installation CD (accurately speaking, a bootable USB flash drive with the installation files), not to say someone should deny the Linux approach. Below is a sketch of what I did:

Step 1: Creating A Bootable Flash Drive with the Windows 7 Installation Program

A Windows 7 installation disk provides tools to diagnose and repair startup problems. For someone with a Windows 7 machine that can burn a CD, he/she can simply "Create a System Rescue Disk" from the Windows 7 backup and restore center. Such a rescue disk should be more lightweight than a full installation disk while allowing you to achive the same result. Back to my case, I was not able to create a rescue disk. What was worse, my Windows 7 installation DVD's were not functioning on my T400. Thus, I decided to create a bootable flash drive with the Windows 7 installation iso. I used Pen Drive Linux's USB Installer for this purpose (ref4).

Step 2: Boot from the Installation Flash Drive and Repair

With the Windows 7 installation flash drive inserted to my T400, I booted the machine from the USB drive. When the installation program fully loaded, I accepted the default language, time/currency, and input settings and proceeded to the following window:

I clicked the ''Repair computer'' link instead of ''Install now''. Then, the problem detected which version of Windows was installed and needed to be repair. In the given list, I selected my only listed Vista and continued. Then, a new window as below popped up with multiple options.

I tried "Command Prompt" first, and typed in the following commands to repair sepcific items:

bootrec.exe  /fixmbr
bootrec.exe  /fixboot
bootrec.exe  /RebuildBcd

Every stroke seemed to return a success. But due to an uncertainty, I double killed this problem by clicking "Startup Repair", too. My long-missed Vista was eventually back after a restart.