The boot manager is attempting to boot from a non-system partition, this parition was likely set as active without a full installation of a new operating system on it.

Is it possible that you just need to install the Windows 7 operating system on this new partition you are booting from? Place and boot the Windows 7 installation disk. After all, you hid and deactivated your Vista partition.

If you have installed both operating systems and still have no access, you have a couple of choices here:

1. Wipe your drive and start fresh, first installing Windows 7 and going through a procedure to install Vista as a secondary. Dual boot is integrated into 7 and Vista now so no separate boot manager is required. My procedure is typically for when XP is the primary partition on the system.

The following guide will walk you through it.

http://www.techspot.com/guides…..-windows7/

2. If you have critical data on the system and it is not backed up, you will want to attempt to create a recovery boot disk utilizing a separate computer.. Boot-US's website is currently down for me to share links on how to do this. It is a complex method so hopefully you can get away with the first option.