Installing 64 Bit Windows 8 From 32 Bit Windows 7
After the Windows 8 unveiling on Monday at the BUILD conference in Anaheim, the number one visited site was the blog of Scott Hanselman where he explains how to install Windows 8 to a VHD and boot to that VHD.
I followed his instructions step by step, but I had misadventures early on when the tool to make a bootable USB drive with the x64 ISO failed saying it had copied the files, but it couldn’t make the USB drive bootable.
At first I thought this was because the contents of the .ISO were more than the 8 gigs I had on my USB stick. Turns out the ISO is only 5 gigs when mounted. I had plenty of room free, but I couldn’t figure out why it wasn’t working.
The short answer is you can’t use the Windows 7 USB/DVD download tool to create an x64 bootable USB stick from a 32 bit OS.
I am running Windows 7 32 bit on a 64 bit machine. Why? Because the company I work for does not support 64 bit machines - specifically in the areas of VPN and Corporate Anti-Virus / Patching. I knew my machine was capable of running a 64 bit OS and I really wanted to get my hands on the developer tools.
I set out to make the disk bootable on my own.
Before you do this, you will need a copy of Windows 7 x86 or Windows Vista x86. You are going to need this to make your USB stick bootable.
So instead of running the nifty tool Scott showed in his post, I used DISKPART to format the USB drive, make it bootable using a Windows 7 x86 installation DVD, and then copy the files from the .ISO over.
First, mount the Windows 8 x64 ISO. Right-click the ISO file and select “Mount”.
After you do this, the ISO will appear as a drive under “My Computer” where you can see the contents of the disc. It’s 4.83 gigs total.
Now we need to start working on the USB stick. I had an 8 gig stick. Go ahead and insert your USB stick and fire up a command prompt. We are going to use DISKPART to select the USB stick as a disk and format it.
WARNING: Be VERY careful during these steps. If you are not careful, you can erase your hard disk. Just look in the comments if you don’t believe me.
SELECT DISK 1 (replace the number with whatever disk number your USB stick shows up as)
CREATE PARTITION PRIMARY
SELECT PARTITION 1
FORMAT FS=NTFS (This can take a while)
OK, now our USB stick is formatted and ready for us to make it bootable. This is where you will need your Windows 7 or Vista 32 bit install disc. Assuming that your install disc is in drive D and your USB stick is drive F, you will use BootSect to make the USB stick bootable in the following manner…
D:\BOOT\BOOTSECT.EXE /NT60 F:
Now copy over the contents of the .ISO file. Open up the mounted drive, select all and copy over to your USB stick.
That’s it! You’ve just created a bootable USB stick containing 64 bit Windows 8 from a 32 bit version of Windows.
You can now pick up with Scott’s excellent article where he boots to the USB stick.