How to check if Win 7 disk is 64bit and what version?

I've got a DVD that I've burnt from an MSDN ISO. I'm not entirely sure if its Windows 7 64bit or 32bit.

How can I be sure?

Quickest way is to go to the drive root. If you have a file named Bootmgr.efi you are running a X64/64-bit version.

Next way is disk size, the x86/32-bit version comes out at ~2.32GB whilst the x64/64-bit version comes out at ~3.0GB.

Lastly, you can go to the drive root and open the autorun.inf file.

In notepad, the 64 bit version shows:

[AutoRun.Amd64]
open=setup.exe
icon=setup.exe,0

[AutoRun]
open=sources\sperr32.exe x64
icon=sources\sperr32.exe,0

The 32 bit version shows:

[Autorun]
open=setup.exe
icon=setup.exe,0

Best and quickest way to answer the question about both Processor architecture and Windows version is:

Use DISM on install.wim.

1. Click "Start", type "cmd", press "ENTER".
2. Type or paste: dism /get-wiminfo /wimfile:"f:\sources\install.wim"
   (Replace f: with drive path to installer root).

Deployment Image Servicing and Management tool

Version: 6.1.7600.16385

Details for image : f:\sources\install.wim

Index : 1 Name : Windows 7 Ultimate Activated 32Bit
Description : Windows 7 ULTIMATE Size : 8,476,902,704 bytes

Index : 2 Name : Windows 7 Ultimate Activated 64Bit
Description : Windows 7 ULTIMATE Size : 12,075,969,989 bytes

The operation completed successfully.

1. Windows version is on the second line. First two dot pairs are OS version. Third and fourth dot pairs are Service Pack and Build info. See Windows Version Numbers to lookup your version.

2. Processor architecture is explicitly shown in the remainder of the WIM info. In this case, this is a dual installer for both 32 bit and 64 bit processors, for Windows 7 Ultimate.

To know wich edition see the ei.cfg file located in the Sources directory on the installation DVD