Code:
# mount /media/sda2
# rsync -ax /mnt-system/KNOPPIX /media/sda2 &
# dd if=/dev/zero of=/media/sda2/store.img bs=1M count=60000 &
60000+0 records in
60000+0 records out
62914560000 bytes (63 GB) copied, 682.558 s, 92.2 MB/s
# losetup /dev/loop6 /media/sda2/store.img
# mkfs.ext4 /dev/loop6
# losetup -d /dev/loop6
# mkdir /store
# mount -o loop=/dev/loop6 /media/sda2/store.img /store
# mount /media/sdb2
# rsync -ax /media/sdb2/local/ /store &
You have no 'sdb2' partition; and where does the directory '/local' comes from?

And then you wrote:
After starting from HD, I can manually mount this new image file, or I can add the commands to rc.local.
After starting from HD whith my Windows 7 installed on it, I don't know, how to mount with the tools from Windows7-tools this new image file. And where is the "rc.local" of Windows 7?

Or do you need changes of Windows 7 bootloader or are fiddling with VMServer? If so, I can not see the big advantage of your method in comparison with remastering in a virtual machine on a virtual drive.