Upon trying a 3rd party bootloader (loaded from a disc), and trying to boot into my partition "Windows 7", I get "BOOTMGR is missing, Press Ctrl+Alt+Del to restart".
But ordinary booting works fine.
So I'm thinking, that perhaps it's because of my partitions. Upon opening "Disk Management", I notice out of my partitions, "System Reserved", "Windows 7" and "Documents", "Documents" is marked as both System and Active.
I've looked into what an active partition is, and what "System Reserved" is for, so I'm thinking - should I mark "System Reserved" as active? The problem is, all images of Disk Management depicting "System Reserved" have it with both System and Active attributes, and so I am unsure on what to do, and also on why my "Documents" partition even is marked with System and Active.