Boot Windows 7 from partition on Linux: BOOTMGR is missing

Question

I have Debian Linux and Win7 installed on the one machine with grub loader and I need to load Windows 7 from partition with Virtual Box. Here my partiotions:

# VBoxManage internalcommands listpartitions -rawdisk /dev/sda
Number  Type   StartCHS       EndCHS      Size (MiB)  Start (Sect)
1       0x07  0   /32 /33  12  /223/19           100         2048
5       0x83  13  /0  /52  37  /57 /20           190       208896 
6       0x82  37  /89 /53  1023/254/63         61034       600064 
7       0x83  1023/254/63  1023/254/63        554073    125599744 
3       0x07  1023/254/63  1023/254/63        338467   1260341248  <--- here Win7

I tryed to follow this guied http://theunixtips.com/virtualbox-use-raw-disk-to-load-windows-under-linux/ (corresponds to official docs https://www.virtualbox.org/manual/ch09.html#rawdisk)

And make:

# install-mbr --force win.mbr
# VBoxManage internalcommands createrawvmdk -filename /path/win.vmdk -rawdisk /dev/sda -partitions 3 -relative -mbr win.mbr

Then I create virtual box machine from exiting win.vmdk file boot and I see:

MBR 1FA:

I press 'A', then '3' (number of partition) and I see:

BOOTMGR is missing
Press Ctrl+Alt+Del to restart

I have SATA controller for disk.

Please, any help!

Answer 1

I just try to load without mbr, but with grub loader installed on my machine (partition number 5, I think):

VBoxManage internalcommands createrawvmdk -filename /home/tanya/vb/win.vmdk -rawdisk /dev/sda -partitions 1,3,5

And it works!