Yes, that is expected.
The USB drive is seen as a hard disk in VBox - what it more significant though is that in the VM, the USB drive is configured as HDD0 and the virtual HDD is HDD1 - so the 'system boot drive' is considered to be HDD0 (the USB drive).
On a real system it does not happen even if you install from a USB HDD.
You can restore the MBR by running RMPrepUSB - Install grub4dos, as you found.
Topic: Easy2Boot
Date 14/12/2014
By SteveSi
Subject Re: Win7 Setup imgPTN
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