Started DISK OPTIMIZATION-then did a dumb thing!

 I am running Windows 7 64-bit Home Premium with the latest Norton 360.

Last night I started the DISK OPTIMIZATION, set to "SHUT DOWN AFTER COMPLETION", but then immediately ,

without thinking, turned off my power supply and headed to bed..

 Now I have the message "BOOTMGR is corrupt. System cannot boot." I do have access to my BIOS and tried to boot from my optical drive with the Windows 7 dvd, but still get the same message.

 I would like any help or solution that can get the rig booted again. Thank you!