Viata Problem

Ya, Boot from you Vista DVD and choose repair option and follow instuctions.
it will check any previous vista installation on your system an repair it.

Yups dats a ntldr problem
Since u have formatted your C your ntldr must have gone & u have to recreate it
Not sure but u can try this

This is the first thing to look at. Is your system trying to boot from a CD or floppy disk that is non-bootable? Remove the CD or floppy and try again.
Have you added a new hard disk with another copy of Windows installed on the new disk? Have you confirmed that the drives are set properly as Master and Slave?
If steps 1 and 2 do not apply,then it is time to pull out the big guns. Follow steps 4 through 10.
Insert the Windows XP bootable CD into the computer.
When prompted to press any key to boot from the CD, press any key.
Once in the Windows XP setup menu, press the “R” key to repair Windows.
Log into your Windows installation by pressing the “1″ key and pressing enter.
You will then be prompted for your administrator password; enter that password.
Copy the below two files to the root directory of the primary hard disk. In the below example we are copying these files from the CD-ROM drive letter “E.” This letter may be different on your computer.
copy e:\i386\ntldr c:\
copy e:\i386\ntdetect.com c:\
Once both of these files have been successfully copied, remove the CD from the computer and reboot.

Your system should now boot normally. Still having problems? Drop by the forum at lockergnome.com for more help. Registration is free.

Source :Google (ya google before posting)

simple.
insert vista dvd n boot into it.
go to repiar- and then the startup repair option
reboot, remove dvd and ur back into vista.

Repair your vista from repair disk

Yeah try to repair with the Vista Installation Disk.Most probably you wont loose any data , however in the rare case it disappears you may need to edit the boot.ini file