When Windows 7 is installed in a logical partition and the primary partition that normally contains Windows 7's boot loader files is deleted, 'Startup Repair' in the Windows Installation DVD can easily fix it.

It seems to be necessary to run 'Startup Repair' twice in succession to accomplish that.
The first run of 'Startup Repair' takes a long time and creates an new 'System Reserved' partition for the boot loader files if there is free space in the hard disk and a primary partition slot available in the MBR.
The second run of 'Startup Repair' seems to complete the job, I'm not sure exactly what it does but it seems to be necessary for Windows 7 to boot up.

I'm surprised how hard Windows 7's automated 'Startup Repair' tries to fix Windows 7.