Installing 7 on usb hard drive, 0x80070026

Hey 7 Forums--
I am installing Windows 7 from a 7 Ultimate disk burned from a trial .iso from my friend.

I want to see how it will perform on my computer and booting from a usb hard drive (my area of experience is with Linux, Ubuntu and variants specifically).

It is not normally supported (windows will refuse to install over usb), but the friend who gave me the disk has used this tutorial

( Sign in to your Microsoft account ). I know it says for Windows 8, but the friend has done it with Windows 7 using the exact same disk and hard drive he gave me.

I follow the tutorial and copy all the files from the disk to the hard drive.

When booting, the Windows setup loads, and I click install.

It gives me this:

Windows cannot open the required file C:\Sources\install.wim. Make sure all files required for installation are available, and restart the installation. Error code 0x80070026.

This is the third time I've tried recopying the files.

I have checked and install.wim is indeed present on the hard drive and the install disk (albeit at 0kb file size).

Could someone please point a friendly noob in the right direction?

Thanks,
savag3

You cannot install to an external HD. Plug it in internally or use another.

Unplug all other HD's and peripherals,

Boot into BIOS setup, reset to defaults, save changes. If an EFI BIOS you'll need to decide if you want UEFI BIOS vs. Legacy BIOS. If UEFI follow these special steps for Install, otherwise enable Legacy BIOS or Compatibility Support Module to proceed with normal install:

Set DVD drive first to boot, HD second, set SATA controller to AHCI, Save changes and Exit.

Then boot into Windows 7 installer DVD or flash stick burned or written using tool and latest ISO for your licensed OS version here. I would use a fresh ISO written with tool in Step 2 as yours is in question.

At first installer screen Press Shift + F10, or enter System Recovery Options to open a Command Box, type:

DISKPART
LIST DISK
SELECT DISK 0 (after confirming Windows 7 target HD #)
CLEAN
CREATE PARTITION PRIMARY
FORMAT FS=NTFS LABEL="WINDOWS 7"
ACTIVE
EXIT
EXIT

Next click Install Now, then Custom install to Clean Install Windows 7 to the partition you created. If it fails then report back at which step and the verbatim error message.

In addition read over these steps to understand the tools and methods which work best to get and maintain a perfect Clean Reinstall - Factory OEM Windows 7. The steps are the same for retail.

After install you can adjust partition size or Create new partitions for data, etc. in Disk Mgmt. You are creating the partition here for the purpose of wiping the HD and marking Active which overcomes certain install failures.