Bootmgr is missing in MS VPC

I am trying to install Win 7 in MS Virtual PC 2007.
At startup I get an error :
"Bootmgr is missing; press ctrl+alt+del to restart"
No OS is installed in the VM.
How to solve this error?

Here's the screenshot of the error!

i had the same go into bios

in advance

then hard drive priorty

change the drives from your 2nd to the main drive where your os system is on

this just happened to me

This is not working, I tried it earlier too , but the problem has been resolved.
I used my old VM that I created earlier

But I get an error during installation of Win 7 RTM
Thank you