Boot into Win7 DVD, select Repair console, click through to Recovery Tools list, open a Command Line, type:

DISKPART
LIST DISK
SELECT DISK 0 (confirm this is Hard drive A)
LIST PARTITION
SELECT PARTITION # (replace # with System Reserved partition #)
ACTIVE
SELECT PARTITION # (replace # with Windows 7 partition # on Drive A)
INACTIVE
SELECT DISK 1 (confirm this is Disk B you want to wipe in order to clone from Disk A)
CLEAN ALL (zeroes the HD, deepest clean, takes awhile - remove "ALL" if you don't want to wait)
SELECT DISK 2 (confirm this is Hard drive C)
LIST PARTITion
SELECT PARTITION # (replace # with Original System K: partition #)
INACTIVE (why was this ever marked active??)
EXIT

Now return to Recovery Tools list to run Startup Repair up to 3 separate times with reboots to write System MBR to System Reserved partition, now marked Active.

You need to ignore offered Repairs and click through to run Startup Repair repeatedly as stated earlier. If this fails, open a Command Line, type: bootrec.exe /fixboot and bootrec.exe /fixmbr, then again try Startup repair until Win7 starts.