Motherboard replaced, drive letter screwed, not booting

I have replaced the motherboard of my computer (with the same model), reattached every device, (I have 3 physical drives, with few logic drives inside). Not my computer boots up, but when windows 7 starts, I get the choice to try to repair or boot. The second one fails with error 0x7B. If I go with the recovery and I look at the log, or I open up the terminal, I see that all the drive letters are screwed up, for examples, it says that Windows is on "M:" (It was C:). How do I change the drive letters for all the logic drives from the recovery?

EDIT: I've unplugged any other drive, but now the assigned letter is "I". If I run Diskpart with command "list Volume" this is the output:

volume 0  C  System reserved  NTFS 
volume 1  I  Win 7            NTFS
volume 2  D  Data partition   NTFS 
volume 3  E  Data partition   NTFS
volume 4  F  Swap             NTFS 
volume 5  G  Data partition   NTFS
volume 6  H  Data partition   NTFS

I have used Diskpart to reassign letters the right way, and I've done fixboot and fixmbr after replacing letters, but as soon as I reboot, everything goes back as listed by diskpart. I need also to leave the reserved system without letter, but it gets C assigned automatically :\ If instead of recovery, I try to boot, I get BSOD with error 0x0000007B