I currently have Windows 7 x86 installed on my computer. I want to install Windows 7 x64 on a different partition on my computer. However there is a little issue, I cannot run the x64 install from Windows 7 x86 which I currently have.

I was planning to Install Windows 7 x64 on another partition to then boot up from that partition to install it on the partition I actually want my OS on. Once that is complete I could just format the partition from the Windows 7 x64 that I didn't need anymore. But the installer will not run from the x86 version of Windows 7 even though I do not want to upgrade that Windows directly.

The reason I'm doing this in such a weird way is that my optical drive is broken and I'm really not into buying a new one since I would use it like once every year or so. I also don't have a USB Flash Drive which is big enough to hold the installation files.

As far as I'm aware I cannot use an external hard drive such as this one, which I do have. Are there any alternatives in which I can install Windows 7 x64 or am I forced into buying a USB Flash Drive or new optical drive?

Thank you in advance for your replies.

Edit: Partitions
This picture shows my current partitions on my laptop. I want to get Windows 7 x64 on the C partition but have to install it first on the F partition to then boot up the F partition windows to format C and install x64 on that one. My external drive is J.

Edit 2: No alternative computer which has a DVD drive, install files are located on an iso from MA3D. To install my 32 bit version I mounted the ISO in Daemon Tools to replace my Windows Vista but since I cannot run 64 bit into my 32 bit OS this doesn't work.

Edit 3: cmd bootsect Following this guide the above screenshot shows me another problem. I cannot update my USB external HDD with BOOTMGR compatible code because I'm on x86 Windows 7. Seems I'm forced into buying a new optical drive after all.

Edit 4: I'm going to try to create the boot HDD with the setup files in a virtual machine with the x64 windows 7 installed.

Edit 5: Solution in my case: Installed a virtual machine with x64 then made the USB external into the boot device and installed it. So this solved my problem.

  • Why can't you just boot from the CD and run from there? It should let you multiboot, afaik the bootloader doesn't care about the OS architecture... – Matthieu Cartier Jan 10 '11 at 15:18
  • My DVD drive is broken :P. It only runs a few DVD's/CD's. – Citroenfris Jan 10 '11 at 15:20
  • Do you have a spare computer that you can set up as a server to boot up over LAN? – Doug A.K. Jan 10 '11 at 15:25
  • I don't think my other PC has a DVD drive either, it's pretty old. Oh well guess I'm forced into buying hardware I'll only use once! – Citroenfris Jan 10 '11 at 15:34
  • Since your optical drive is broken, I assumed you were using an ISO or other CD Image file along with an image mounting utility. Running on this assumption, I then assumed you could set up the boot server software on another computer and transfer the cd image file. – Doug A.K. Jan 10 '11 at 15:58

You can "burn" a Windows 7 .ISO to a USB drive & install from there, http://store.microsoft.com/help/iso-tool.

AFAIK, so long as Windows (your BIOS actually) can see your Passport - as a boot device, you should be able to use that.


I don't think you can upgrade from 32-bit to 64-bit so the only option for you is to run setup from boot. You will need to make the partition before this so that you can keep your x86 file system intact.

I am not up to date on software that can perform a live disk partition as most people do a format to do this. Have a look on Google, they are normally easy to find.

  • I know you cannot directly upgrade from 32 to 64, I don't want to do that either :P. The problem is that I cannot use a DVD or USB Flash drive. I'm looking for alternatives if they exist! Edited my question to show you my current partition situation. – Citroenfris Jan 10 '11 at 15:15
  • only other option then is move hard drive to another comp/laptop you can use a disk in or try research how to over the network i have never tried this but hear it can cause problems – madyotto Jan 10 '11 at 15:24
  • ok now i am confused after reading your post you say you have tired to load win 7 64 setup from your 32bit but the only way to open any windows setup from an original install is for upgrade only – madyotto Jan 10 '11 at 15:29
  • why can you not use a dvd drive ? if you are not using any dvd or usb how are you attempting to run this setup file – madyotto Jan 10 '11 at 15:30
  • I have an iso file from MA3D. – Citroenfris Jan 10 '11 at 15:33

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