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I wanted to know if there was a way (that worked!) to both Install and Run Windows XP Pro from a USB 2.0 connected Hard Drive. My system does allow to boot from external usb hard drive, but when I tried to install Windows XP to the USB HDD, it didn't allow me to.

My ultimate goal is to be able to move only the hard drives (w/ windows installed) to other identical systems, in times of maintenance, etc.

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migrated from Nov 10 '09 at 12:34

This question came from our site for system and network administrators.

I think we should put XP in trash can. Using Ubuntu would be a better choice. – UltraDEVV Sep 24 '14 at 13:57
Can be done – Moab Oct 16 '15 at 21:16

The Old New Thing: Why can't I install Windows on my USB drive? (April 15, 2004)

[...] Another reason not mentioned in this paper is that during any hot-plug operation, the USB bus is completely reinitialized. Windows really doesn't like it when it loses access to its boot device. [/...]

The whitepaper mentioned there is Recommendations for Booting Windows from USB Storage Devices.

Possibly related: A Deep Dive into USB Boot (MSDN)

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The trick is actually on the BIOS to properly emulate a Int 13h device for the Master Boot Record. I've found the ASUS motherboard do this properly.

One "trick" I've found is to install it to a normal SATA drive then migrate the actually HDD into the USB case. This generally works as the USB drivers have already been installed into the "kernel space" during boot, and the system will continue.

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I'm pretty sure that no Windows variant is happy booting from a USB mass-storage based drive, unfortunately. There are a couple of other options though.

If you have an eSATA port on the machines, or install one with an add-on card, I'm told that Windows tends to see these as just another SATA drive (assuming your machine will boot off it).

If you are not using the machine for 3D work or anything that imposes a large I/O load, you could run your main Windows install in a large VM on the external drive. Though this way you still have to have the base OS installed on each machine but Debian/Ubuntu+VMWare is not difficult to install and can be cloned easily. Make sure your Windows licenses allow you to work this way though - OEM licenses that come with machines do not allow use in a VM.

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Windows PE can happily boot from USB, but the point is academic as PE isn't suitable for real-world end-users. – mh Nov 10 '09 at 9:49

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