Yeah, I left out something extremely important: don’t forget that the emulated hardware inside the “box” will almost certainly be different from that recorded by the OS when it was originally installed. For example, VirtualBox will typically tell the “box” that it has a PCNet NIC, where you might actually have a Broadcomm or some other brand. When you originally installed the OS, it would have set up the drivers for your actual NIC. When you boot that same OS under VirtualBox, it’s going to see different hardware.
Programmer768 said: Because I guess the identifiers of the drives are different between the PC and VirtualBox.
This is just one example. The video will almost certainly be different as well. I’ve already mentioned the NICs.
It’s my understanding that this is the biggest “gotcha,” for example, when trying to virtualize an existing Windows installation. Windows will typically refuse to even start, and even if you could get it to run, it will probably bring up the dreaded “you need to re-register this copy of Windows” dialog. I did a Web search and found a page that offered steps to get around this, but it involves hacking (and I do mean, “hacking”) the registry.
OK, suppose you do that: you get Windows to use the “new” Virtualized hardware, and it’s running fine in the “box.” But if you were then to boot directly into that Windows partition again, outside of VirtualBox, the hardware drivers would be wrong again. Even after you got that sorted it would probably ask you to register yet still AGAIN!
(Ah, one of the nice things about F/OSS software – no stupid activation codes, or “You Must Register” boxes, or any of that nonsense!)
I was fortunate enough to have two copies of XP here (… hmmm … should we use the word, “fortunate” for this??), so when I started using VirtualBox, I left the original Windows XP intact in a dual boot, and installed the spare copy of XP in a “box” so that I can dip into Windows on those rare occasions when I think I need to punish myself.