Overcoming problems encountered when installing Windows 7 from a USB key

USB installations of Windows have been, in my experience, fussy. They rarely work out of the box.

If you have a DVD drive, it is best to make an installation DVD and use that.

But what if you do not have a DVD drive? Here are some problems I have ran into.

I should note that I am assuming that there is nothing left on your hard drive that you want to save (it will all get erased).

Problem: when you click on "Install now", you get an error message about missing drivers.
Solution (tried and true): see a previous post.

Problem: at least you get to this screen

but when you click "Next", it's a no go. You get the message "Setup was unable to create a new system partition or locate an existing system partition. See the Setup log files for more information".

Solution (work in progress): Copy the installation files to the hard drive, then reboot and run the installation off the hard drive.

Details:

First, we need to go to command prompt. Close the installation window, and say "yes" to canceling the installation. It's not going well anyway. This will kick you back to the "Install now" window. Find the small print "Repair your computer" at the bottom left and click that.

Select the first option on the screen (Use recovery tools...), then click next.

Select "Command Prompt"

You should now have a black command prompt window, in which you must enter some commands.

The following are instructions I found here and here, with some detailed filled in and explained.

First you need to prepare your hard drive for the files.

1) Type
diskpart

This launches a utility that allows to format disks and make partitions (more on this post).

2) Check that your hard drive is not gpt (not good for Windows 7). Type
list disk

If you have a * in the Gpt column, your drive is gpt and it needs to be changed to mbr for Windows 7 to work.

If there is a * in the Gpt column, then type
convert mbr

If you do a new list disk, the * should be gone.

3) Next type
list vol

This will show you the partitions on all the disks in your system (though your solid state hard drive may be missing - a battle for another day)

In particular, in the "Ltr" column, you may recognize drive letters that appear when you use file explorer in Windows. This is a good opportunity to note what letter is assigned to your thumb drive. You will need to know that.

If your c drive appears on the list and is already formatted properly (NTFS), you can skip the formatting and partitioning (steps 4 - 9) and exit diskpart.

4) Make 100% sure that you have identified the hard drive where you want windows and note its number (e.g. is it Disk 0 or Disk 1,...?). Type
select disk=0
if Disk 0 is your hard drive.

5) Now format that disk by typing
create partition primary

6) Look at your partitions now by typing
list vol

7) Note the number of your new partition (or volume) then type
select vol=1
if your new partition is under volume 1.

8) Now we are going to format that volume. Type
format fs=ntfs quick

9) Next type
assign

10) Now exit diskpart by typing
exit

Next you want to make your hard drive bootable.

11) Get on your thumbdrive by typing
d:
If your thumdrive was under letter D.

12) Now we are going to copy the contents of the thumb drive to the hard drive. Type
xcopy d: c: /e /h /k

13) Navigate to the boot folder on the thumb drive by typing
cd boot

14) To make your hard drive bootable, type
 bootsect /nt60 c:

We are done with that part. Close the command line window and click "Restart". When the Dell logo appears, hit F12 for boot options. Choose your hard drive and hit [Enter].

If the computer does not restart, boot with the USB thumb drive again and repeat the procedure above from the beginning until you get back to the command prompt window. You can skip the whole partitioning and formatting business. Go to step 14 and add the /force option to the command we typed. That is, type
 bootsect /nt60 c: /force

Note that the command will fail if you type the "/force" before the "c:". /force must go on the end of the command.

Reboot, see if you have better luck this time booting from the hard drive.