Heyy, welcome to Vista Forums!

Have you tried startup repair?

• Insert your Windows disc and reboot the computer, then go into the BIOS and change the first boot device to your CD/DVD device, save and exit. The computer will reboot.

• Once the computer has gone through post and initialised, it should say something like "Booting from CD/DVD, press any key to continue" just hit enter.

• The computer will boot from the Windows disc, this bit takes a while, but once its done, a menu will come up asking what you want to do. Click "Startup repair" from the list.

• So now it will search for hard drives with Windows. It might look like it has frozen up, but be patent. Select the correct drive from the menu and click the repair button.

• So now its going to attempt repairs on the drive, replacing missing or corrupt Windows files. This might look like its frozen and it does take a while, depending on the size of your hard drive, but again, be patient.

Once it has finished it will ask you to take the Windows disc out and reboot your machine. If there was an error, it will say what the error is.
Its up to you if you want to change the first boot device back, but i have mine set for CD/DVD since i install different versions of Ubuntu alot.

I hope this helps you!
Please post back with what has happened, if it worked, or if you need anything explaining!

Daniel