How to dual boot Win 7 64-bit and Win 7 32-bit

I want to set up a dual boot between Win7 Home Edition Premium 64 bit and same 32 bit. The machine came with the 64 bit W7 already installed. I bought an extra W7 package. As received, the disk is set up like this : one primary 19 GB partition for restore, one primary, active partition called "system reserved", of 100 MB which contains only the set of boot files, and one primary with all the Windows files (C: ), which I have shrunk to 125 GB. Behind that, I have created an extended partition with several logical drives. At this point, this works OK.
I want to install my 32-bit Win 7 on the second logical drive (E: ), hoping it will "share" the 100 MB "system reserved" boot partition. Will there be any problem between the boot files of the 64-bit and the 32-bit versions in the same partition – they probably have the same names, may be they are the same? Would I need to enlarge the system reserved to 200 MB? Would anyone suggest a better way to add the 32-bit OS?

It should not create a problem. Windows 7 is fairly good at managing the boot sector... and yes it should only need one for both installations. They can share the boot record. The hurdle to overcome was the second activation key. Which you have apparently already taken care of

Thanks, that’s good news. Having all the boot files in a single, active, "system reserved" partition will only really make sense if this partition can be common to all the OS’s in the computer. But, once I install the additional (32-bit) Win 7, what happens with the existing 64-bit boot files in the "system reserved" partition? I guess the 64-bit bootmgr, bcd, etc files will be overwritten by the 32-bit ones (same filenames)? Can I still boot correctly my 64-bit Windows OS with the 32-bit boot files? Last question: if the 64-bit boot files have been overwritten by the 32-bit ones, will EasyBCD still find the necessary information to set up a valid link to the 64-bit Win 7?

the 100mb reserved partition is only the boot manager really.
and it can handle multiple copies without a problem.
you could actually put vista in there too, the problem at that point would be too many partitions on the drive I would think though.

Maguscreed is quite right - the system reserved partition will take care of the boot files.
When you've installed your second copy of Windows you'll find the boot menu on startup will show two entries both with the same name - typically Microsoft Windows 7.

This tutorial explains how to edit this information, which will help you to boot into the right OS.

http://www.sevenforums.com/tutorials/5110-dual-boot-change-os-name-windows-boot-manager.html

To repeat: You should not need to use EasyBCD - Win7 32 bit should configure the Dual Boot Menu for you.

You did the partitioning exactly correct as far as I can tell without seeing a screenshot of your Disk management.

One last question before I go ahead with the dual boot install: The first partition on my disk (even before the 100 MB "system reserved" partition) is a 19GB OEM partition which has no name and seems to be not accessible by the Windows partition manager. As far as I understand, it is there for the backup/restore system and it seems to me that Windows is automatically recording in there on a continuous basis its "current state", so, in case of a system trouble, I can "revert" to a previous, sane state. Now, what happens when I have a second instance of Windows - a 32-bit one - which might also be writing into this partition ? How can I avoid a conflict? Is there a way to inhibit "a" Windows from accessing this partition ? Thank you.

The oem space contains a image of the computer as it was out of the box, and in some cases certain user data is backed up, it's not something I would be counting on though.

Whenever I have a physical copy of the user's windows 7 disc, I generally consider it safe to remove that partition (I usually use acronis, because as you noted, windows disk management has been specifically blocked from messing with it, though I think it's more to keep people that don't know what they are doing from wiping their own restore partition. )

The current bootmgr you are using is already accounting for this or you wouldn't be booting as it is. removing it now, may be more trouble than it's worth.... I do not see how the additional copy will cause any trouble as it will simply be added to the boot list of the currently used bootmgr.
i.e. - not a whole lot is really changing on the boot front.

The 19GB partition will no doubt be the factory recovery partition.

If you have created a set of recovery discs (if not, I suggest you should before you go any further) then you can delete this partition. A set of recovery discs will allow you to recover your computer to its factory state should you need to do so.

If you don't want to delete it you can always go into Disk Management and hide the drive letter so that Windows can't see it.

I have now attempted to install a 32-bit Win 7 as a dual boot with an existing 64-bit Win 7 the way described in the thread (custom install, on a separate partition). Unfortunately, it did not work out the way I hoped. At first, the install went very smooth and it was nearly finished when I got a window that said (my translating from French) : "The Windows Installer program has failed to setup Windows to be run on the hardware of this computer". I retried two times,
to no avail. There was no way to have a diagnosis of the problem. Could it be that the processor of my machine, a 64-bit Intel Core i7 2600 does not support a 32-bit OS ? I have looked up the specs of this chip on the Intel Website, but there is no clear-cut answer. What other reason could it be that it does not work ?
If installing a 32-bit Win 7 as second oS appears to be impossible, I shall have to install a second 64-bit one.
In this case, how can I cleanly uninstall the windows 32-bit that does not work and the two-line menu boot manager window ?

Format the 32 bit installation partition using disk management from your 64 bit install.
Your CPU should have nothing to do with the problem. Set your BIOS to default settings and try again. Take note of the settings in your BIOS as they are now. ( Write it down if you have to. )

Try install again after following AddRAM's suggestion to reset BIOS to defaults, delete and format the target partition.

This time enter Device Manager during install if necessary to uninstall any devices in error (likely display driver) to see if install will complete, then update device drivers from desktop. Device Manager - Access During Windows 7 Installation

Where did you get the Win7 installer? Did you burn the DVD yourself?

What do you mean by default settings ?
My bios-setup, as purchased, was: 1. [EFI device], 2. [Hard disk WDC WD20E....], 3. [CD&DVD: ATAPI DVD.....], 4. [Removable device], 5. [LAN]. I just swapped 1 and 2.

For the install, I just hit F12 on bootup, then got a menu where I selected to boot from the DVD device (= with my Windows DVD inserted). What's wrong with that ? Of course, I have no control of the device Windows boots from when it does its several restarts...

Clear CMOS - 3 Ways to Clear the CMOS - Reset BIOS
is how to reset the BIOS which can solve the issues in some cases.

It takes special steps to install Win7 on an EFI mobo: UEFI (Unified Extensible Firmware Interface) - Install Windows 7 with - Windows 7 Forums.

I'd enter BIOS setup to see if EFI is enabled, follow the steps given above.

Gregrocker's tutorial on how to access the device manager during windows installation has really helped me a big step forward. At least, I know what's wrong, but I cannot (yet) put it right. The instance of Win 7 (32-bit) which I have
installed is actually fairly completely installed, but all it does on startup is displaying me its problem window. So I did F8 on booting, selected safe mode and eventually shift-F10, etc and I got the Device Manager, showing me the devices that are not working: 1. "SM bus controller" (what is that ?), 2. "Ethernet controller", 3. "PCI controller for simplified communications" (what is that ?). Looking at these devices more closely, I noticed that they don't have a driver for them. I thought, I could start with the Ethernet controller by looking in the device manager of my other instance of Windows 7, the 64-bit one, and downloading the 32-bit version from the supplier (Intel Gigabit 82579V). This way, I got a file from Intel that is described to provide all the drivers required for all the Windows 7 versions, including mine. But this file (which I downloaded) is an "exe" file, and I cannot run an exe file under an operating system that does not work. Any advice on how I could get the right drivers out of that .EXE file into the different directories of my unable instance of windows 7 ?

I don't think these chipset drivers would stall installation by their absence, or if they are it is a rare case. The deal killer at this stage is normally the Display driver. What does it show and in what state?

You'll need to get to the desktop to run the .exe then browse into the extracted files from missing Device to Update Driver. Or you can simply run the chipset although Win7 may have provided drivers it prefers for other chipset elements.

I think the first thing you need to address if if you have an EFI BIOS (as it would seem from the boot order listings) and if so follow the steps given here to install: UEFI (Unified Extensible Firmware Interface) - Install Windows 7 with - Windows 7 Forums

The missing chipset drivers are the only ones with a yellow exclamation mark. For the display, it reports a "generic VGA", no problem symbol, obviously the default windows VGA display driver. The machine has a NVIDIA GeForce GX550Ti graphic card which works well in the 64-bit instance but which I don't intend to activate in the 32-bit instance of win 7.(on another machine, I have a similar setup with xp: the graphics card died after 4 years, so the "primary" instance of my dual boot became unusable (black screen), but I could still access all my data with the secondary instance which had been left under the VGA of the windows VGA controller). By the way, could you confirm whether the 32-bit win 7 has a compatibility mode with 16-bit apps ? I still have some good ones which get rejected by the 64-bit win 7, so I would expect this at least from the 32-bit version.
The only way I could run the .EXE drivers file at this point would be under the 64-bit win 7 instance. If I do execute it that way, what will happen ? will it just unload all the files it contains onto an unzip-directory or will it outright install and interfere with my installed 64-bit drivers ? Regarding the EFI bios, as I said, I have moved the hard disk option into the first place and the EFI second and I found no change to the bootup speed which comes near to a "kickstart" - at least compared with good old win 2000 I have on another machine. But, as I already said, for the install, I use F12 and the CD&DVD menu-option, so this should logically not be involved with EFI ? My machine is actually sold as a "gamer" and there is no 32-bit version on the market, so I am not sure there are all the 32-bit drivers possibly needed. So, this exercise could become pretty difficult.

If you have an EFI BIOS on the machine you need to use the special install steps. I'll ask you again to go into BIOS setup to look for what EFI settings are there and how they are set. These are not boot order settings, but the most fundamental BIOS settings.

You cannot insert any element of the chipset into the Win7 installer except SATA controller which is only needed if the HD or partitions do not show up on drive selection screen.

You'll need a Vista or WIn7 driver for Display to replace VGA if you want better resolution or Sleep/Hibernate.

You cannot insert any element of the chipset into the Windows 7 installer except SATA controller which is only needed if the HD or partitions do not show up on drive selection screen.

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This isn't entirly true if the driver is in the inf form. I know my intel chipset drivers can be downloaded as a zip and when extracted they are just inf files.
Add Device Drivers During Windows Setup

By adding device drivers during the windowsPE or offlineServicing configuration passes, you can add out-of-box device drivers to the Windows image before the computer starts. This method can also be used to add boot-critical device drivers to a Windows image.

If you need boot-critical drivers for Windows PE, use the windowsPE configuration pass to reflect the drivers before the Windows PE image is booted. The difference between adding boot-critical drivers during the WindowsPE configuration and the OfflineServicing configuration pass is that, during the WindowsPE configuration pass, boot-critical drivers are reflected for use by Windows PE and other drivers are staged to the Windows PE driver store. Then, during the offlineServicing configuration pass, the drivers in the Windows PE driver store are staged to the driver store on the Windows image.

Click to expand...

I also know you can put a folder called $WinPEDriver$ on the root of the Win 7 DVD or USB drive if installing from a USB drive and place your drivers in there, subfolders are ok, and the drivers will be loaded. Not sure if it'll work placing the folder on a USB drive that is not the installation media.

Then there's the offline option.

The thing is when non boot-critical drivers are installed, I don't think this happens till Windows boots for the first time.

Here's a couple of other links for more info
Understanding Device Drivers and Deployment
Add and Remove Drivers Offline

I forgot to mention if the EFI stuff which I know nothing about doesn't work you can always check the setup log, even though that's not always helpful.