What you need to know about the Windows 7 Release Candidate

What you need to know about the Windows 7 Release Candidate

Summary: Microsoft has finished its work on the Windows 7 Release Candidate and has announced a distribution schedule. For those who are thinking of evaluating this release, I’ve put together this FAQ.


Updated 5-May

Microsoft has finished its work on the Windows 7 Release Candidate and has announced a distribution schedule. For those who are thinking of evaluating this release, I’ve put together this FAQ. If you have any additional questions, ask them in the Talkback section; I'll update this post as needed.

What is the Windows 7 Release Candidate?

The Release Candidate (RC for short) is the most recent milestone build in the Windows 7 development process. The official build string is 7100.0.090421-1700. It is available in x86 and x64 formats.

Update 5-May: The Release Candidate code is available for update here.

Will there be additional release candidates after this one?

That’s not in the plan of record, and it’s unlikely to happen. Interim builds will be prepared between now and the final release for testing internally at Microsoft and externally by OEM partners. But this is the final version that will be made publicly available before Windows 7 is released for manufacturing and sent to retail channels and OEM partners.

Is the Release Candidate feature-complete?

Yes. Rumors that Microsoft is holding back a secret feature or radical change in the Windows 7 user interface are unfounded. Although it's possible that Microsoft will add some new desktop backgrounds or screen savers, what you see in the Release Candidate is what you'll get when the product is released. Microsoft's work from now until then is in fixing the last round of bugs, most of which will be related to OEM configurations and hardware support.

Back in early March, I spotlighted some of the visual changes in Windows 7 that you'll see in the Release Candidate (see "A sneak peek at the Windows 7 Release Candidate"). In addition, Microsoft has announced that it will release a custom version of Virtual PC with a licensed copy of Windows XP SP3 and make the combination available as a download for licensed users of the business editions of Windows 7 (Professional and up). This add-on, called Windows XP Mode) will not be included with the release candidate, nor will it be part of the final RTM product. 

What's changed from the beta release?

A lot, actually. See my review "Windows 7: What to expect" and the accompanying screenshot gallery for more details. 

Will the RC be available to the general public?

Yes. Just as with the beta release, the public will be able to download and install this release for evaluation purposes.

Do I have to pay anything to use the Windows 7 RC?


When will the RC be officially available for download?

Participants in the technical beta program got access to the RC bits on April 30, as did TechNet and MSDN subscribers. You can sign in using your credentials and download the RC code from those sites. The public download site went live on May 4.

What format will the download be available in?

Downloads will be disk images in ISO format, which can be burned to DVD. You can also mount the file to a virtual drive using a program like Virtual Clone Drive. Your CD/DVD burning program may offer this capability as well.

Can I install the Windows 7 release candidate over an earlier beta release?

That depends. If you use the setup files as distributed, you will be blocked from upgrading over any build prior to 7077. That includes the beta release (build 7000) and most leaked interim builds from April 4 or earlier. There is a workaround, however, which I'll document in a follow-up post.

Can I upgrade my existing copy of Windows XP?

No. The XP-to-7 upgrade path is not officially supported. Microsoft has advanced deployment tools to assist with XP migrations in enterprise settings, but for the RC you’re better off using the Windows Easy Transfer utility to copy your data and settings to external storage, then restore it (and reinstall your programs) after performing a clean install of Windows 7.

Can I upgrade my existing copy of Windows Vista?

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<-- Continued from page 1

Yes, with some caveats. First, you must have Windows Vista Service Pack 1 installed; the original (RTM) release of Vista can’t be upgraded. In addition, you can upgrade only within the same processor family: Vista x86 to Windows 7 x86, and Vista x64 to Windows 7 x64. You cannot upgrade an x86 machine to x64 or vice-versa. An upgrade installation preserves user accounts and passwords, Windows settings, installed programs, and data files but might replace some device-specific drivers with generic Windows 7 versions. In my tests, Vista upgrades have worked very well across the board. That’s not surprising, given that Windows 7 is based on the same core platform and the same driver model as Windows Vista.

Can I install Windows 7 in a virtual machine?

Virtual machines have their uses, and all of the virtualization platforms I looked at currently support Windows 7 as a guest OS. One major caveat is that virtualized hardware does not offer support for Aero graphics and thus doesn’t give a true picture of the desktop experience. VMs also don’t support direct connections to some hardware devices such as TV tuners. VMs are ideal for testing software compatibility and creating simulated networks.

Can I install Windows 7 on an external USB or IEEE 1394 (FireWire) hard drive?

No. Windows 7 cannot be installed on any drive that Windows identifies as removable. Depending on how your system is configured you might be able to install the OS on an eSATA drive, which appears to the operating system as an internal fixed drive.

Can I choose which edition to install?

The release candidate image is configured to install Windows 7 Ultimate Edition. If you want to choose a different edition, copy the installation files to a different location, delete the Ei.cfg file from the Sources folder, and then run setup from that location. 

Will Windows 7 work with my software? 

That’s one big reason to evaluate this release, isn’t it? Most mainstream business and entertainment programs that work on Windows Vista will also work on Windows 7. Programs that are likely to fail (at least until patches are available) are system utilities that interact with hardware at a low level, such as disk defragmenters, and some security software. If you run Windows 7 Setup from an existing copy of Windows Vista and choose the upgrade option, you’ll get a report listing any known incompatibilities.

Where can I find Windows 7 hardware drivers?

The drivers included with the Windows 7 RC cover a very wide range of devices, and others are available through Windows Update. If you find that a particular device isn’t supported, you should be able to use the Windows Vista driver, although you might have to jump through some hoops to bypass compatibility checks. Some vendors have released beta versions of Windows 7 drivers. Both Nvidia and ATI, for example, have released WDDM 1.1 video drivers for Windows 7. Creative Labs has released Windows 7 drivers for some devices and has announced a release schedule for others.

How long does installation take?

That depends on your hardware and the installation type. A clean installation on a fast desktop system should finish in a half-hour or less. On slower hardware, it could take up to an hour. When performing an upgrade, you'll need to allow additional time for migrating data files and settings. I haven't seen any upgrade take more than two hours.

Do I need a product key?

Technically, no. At the end of the installation process you’ll be prompted to enter a product key. If you leave this box blank, setup will continue and your copy of Windows 7 will work with no restrictions. You will have to enter a valid product key before activating.

I have a product key from the Windows 7 beta. Can I use it on the Windows 7 RC?

Yes, in my testing product keys acquired as part of the beta program work just fine for clean installs and upgrades. Update 5-May: Microsoft says, " Previously issued Product Keys for the Windows 7 Beta are not intended for continued use, we are recommending that you register and get a new Product Key for the Windows 7 RC."

Do I have to activate my installation?

By default, Windows 7 will activate automatically three days after you install it. You can disable automatic activation during setup by clearing the check box below the product key box. If you do not activate at the end of the 30-day grace period, you can continue to use the RC, but you’ll have to put up with nag screens and a forced black background. You can reset the 30-day grace period up to four times, using the same technique that works with Windows Vista.

How long can I use the Release Candidate?

The software will stop working on March 1, 2010, which should be long after the official release is available. You must either uninstall the RC or replace it with a licensed copy of the final RTM code before then.

When will Windows 7 be released to manufacturing?

Your guess is as good as mine. In the words of a Microsoft executive, "Those who know, won't say. Those who say, don't know."

Topics: Software, Microsoft, Operating Systems, Windows

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  • There is a caveat there for 64-bit to 64-bit

    Windows 7's installation will keep on throwing up a error of 'not enough disk space' if you try to upgrade Windows Vista 64-bit SP1 or SP2 RC to Windows 7 64-bit.

    I've tried this on 4 computers now.... all of them give the same warning of 'not enough disk space' even though they have 60, 80, 120 and 400GB's of space free on the C: drive.
    • Hmmm, my only copy is x86

      I upgraded Vista x64 to Win7 x64 build 7077 (RC branch) without incident. But I haven't yet been able to test the RC build.
      Ed Bott
      • Ed, So How Does This Work?

        Right about now I am as miserable a computer user there is.
        Many of my programs which would work under V 32 bit refuse to work in V 64 bit. I see in your blog I would be "stuck" with a 64 bit with the RC; but, will I be stuck with a 32 bit of the Final Release?

        Also, let's say I am stuck with this 64-bit OS, and I buy the Ultimate or one of these versions that will allow "XP Virtualization" will I still be screwed or will the XP V. actually help many of my older apps work? Even though I'm in this dismal 64 bit transistional world of misery?

        Btw, many of the programs are games; such as the confusing Star Wars Empire at War that works, but, the expansion pack, Forces of Corruption that does not. (I'll never understand how THAT happened). But, there are other older programs that I need, such as my research Bible Software program (which apparently cant get updated until courts say they can).

        Ok, more info than needed, but, just trying to figure out what hope I have of fixing things.
        • You can switch back

          You just can't upgrade directly over x64 to x86.

          For your non-games, virtualization is the obvious answer, as the virtual copy is x86. But I don't know how well those games will play in a virtualized environment. I suspect it will be unacceptable.
          Ed Bott
          • Thanks. I have an alternate solution

            Take this hunk o junk back, and just wait til Win 7 comes out later this year.

            I suspect 64 bit wont make its way to mainstream for several years, so, if I get 32 bit version of win 7, then maybe things will work. Maybe not. But, worth a try, i guess.

            Thanks for the response. I was afraid of that, but, I wanted an honest answer. So, thanks.
          • 32bit apps that don't work?

            Batman, What apps would those be? I've been living in 64bit land for over two years and haven't had any problems what-so-ever. And I run Photoshop, Lightroom, Visual Studios and a variety of other 32bit version apps, all with no problems.
          • Not sure

            what the bit rate on them are.

            I have a lot of older games and software titles. I believe the techno term for old software is "legacy software".
            I installed Star Wars Empire at War and it runs fine; oddly, the expansion pack, Forces of Corruption does not work.
            Even more oddly, I have several games that were made for Win 95 that still works great.
            One game I have, Cold War, isn't that old; just apparently poorly written. But, after installing it, I ended up having to reboot; upon reboot, my "bootmgr" was missing. How strange is that? Had to format 3x to get everything almost right. Grrr.

            More oddities:
            only one of my current Bible programs works on V.64-bit, and that is e-Sword. What makes this odd? Vista says it does not work, but, it does.
            My most important Bible software program, however, does not. Gramcord for Windows. I believe that is a 16-bit app. It works in XP (altho, a small download file is needed, to fix the "out of envirnoment space" error) and, it works in V 32-bit. But, not enough 64-bit users have reported in on a work around. And, due to some legal issues they cant upgrade the software.
            Most of my apps and many of the games will work in 32-bit, just not 64-bit.

            Of course, had I known this would be a problem, I'd have never gone to 64-bit. Just not techy enough to understand all this stuff.
            What i'll probably end up having to do is return the computer and wait for a Win 7 system, get a higher end version, and hope XP Virtualization works.

            Ok, here's something else that is weird. I'm not into the latest and greatest, obviously; but, I do tend to stay ahead of a good number of people. I can't imagine the masses being very happy with how things are going right now.
    • Have you tried...

      Have you tried uninstalling your anti-virus?
      That is the only thing that has ever caused me grief when doing upgrades.
    • What you need to know about the Windows 7 Release Candidate

      It's overhyped, and to get it to sell they need to control the OEM's, the media, and of course the blogosphere.

      Actually creating what people want, rather than creating whatever and then trying to condition humans to thinking it is "normal" or "expected" or "great" would be a much better way to do business, and be much more progressive for mankind.

      I guess that's out of reach though.
      • Sounds like someone needs a hug!

        Yeah it hurts at first but if you stop drinking the kool-aid you'll feel much better. Honest!
  • RE: What you need to know about the Windows 7 Release Candidate

    You say:

    Is the Release Candidate feature-complete?

    Yes. Rumors that Microsoft is holding back a secret feature or radical change in the Windows 7 user interface are unfounded.

    May-Jo says that XP Mode 'is the rumored ?secret feature? Microsoft was working on for Windows 7 that some have called ?Virtualized XP."'
    • It's an add-on for some editions

      It's not a new feature, it's an add-on copy of a new version of Virtual PC with a licensed copy of XP SP3. It won't affect the UI at all.

      And of course it's already been announced, so, it's not a secret, either.

      I've updated the post to include a mention of this feature, which will not be included with the Release Candidate or with the RTM edition of Windows 7. You'll have to download and install it separately. (OEMs can choose to preinstall it as well.)
      Ed Bott
    • The Speculative new UI

      What Ed is referring to is the speculation that Microsoft will introduce a new User Interface in the RTM. I believe that Paul Thurrott has been making claims that this is a possibility... and I don't doubt Paul's logic.

      Paul thinks that the Windows 7 'Glass' UI is too similar to Vista's UI thus Microsoft would want to break as much away from the bad (and mostly unfounded) publicity of Vista.
      • New UI

        There are also persistent rumors that Microsoft is planning to replace the Aero UI skin with a new version. I cannot confirm that, however.

        Source: http://www.winsupersite.com/win7/faq.asp
    • Rumor No More

      See the screen shots here: www.winsupersite.com/win7/xp_mode_pre_shots.asp

      Read the full article here:

      want to compare features of each flavor? Go here:

      Window 7 is pure genius; "Seven Rocks!
  • RE: What you need to know about the Windows 7 Release Candidate

    <strong>"Can I install Windows 7 on an external USB or IEEE 1394 (FireWire) hard drive?

    No. Windows 7 cannot be installed on any removable drive."</strong>

    I have Windows 7 installed and booting from an eSATA drive, so maybe USB and Firewire aren't supported, but I wouldn't say that booting from a 'removable drive' is not supported.
    NamelessFor Now
    • Technical distinction

      I'm referring to a drive that is identified by the OS as removable. eSATA drives appear to the operating system as fixed drives, not removable. Needless to say, you want to be very careful not to remove the drive that's running your OS!

      I've updated the post to make this distinction clear. Thanks!
      Ed Bott
    • As I recall ...

      ... when I installed Windows 7 RC on a second partition of my Vista system, it offer to place Windows 7 RC on either partition or on one of my two USB-connected drives.

      I don't think that a USB hard drive is necessarily recognized as "removable" as a DVD+/-RW drive (or even a removable hard drive) might be.

      I think that the important requirement is that the boot manager must be on the boot record of the first hard drive connected to the system and I think that is why installing to a "removable media" drive is not permitted.
      M Wagner
      • It appeared to give you those choices

        The drives and volumes appear in the list of available install locations. However, had you tried to install the OS on a USB drive it would have blocked you. I just checked this on a few minutes ago on a drive that has a boot record. When you try, you get an error at the bottom of teh drive selection window, with a show details button that says the drive is ineligible because it's connected via USB.
        Ed Bott
  • win 7

    windows 7 is the best operating system ever.Even my machine is running win 7 7000 it works fine (64 bit)I have all the drivers (intel P43t, nvidia 8500, and others 64 bit drivers)I can't wait to install RC version, hopeing it's just a bit faster then this Beta I'm running now.
    Just one thing to improve is the performance.
    Koko Bill