In my last post in this series, I discussed the question whether the 64-bit edition of Windows Vista is faster than its 32-bit version. I came to the conclusion that working with Vista x64 only makes sense if you need more than 3GB memory. The other interesting topic is if compatibility to the 32-bit world is still an issue 16 months after Vista’s release. Today I discuss software compatibility, in my next post in this series I’ll write about hardware compatbilty.

Latest posts by Michael Pietroforte (see all)

vista_logoWhen I wrote about this subject shortly after Vista came out, I more or less voted against installing Vista x64. My main point was that Vista will already cause enough compatibility problems. So it is certainly better to limit the number of possible culprits. At that time, I didn’t imagine that Vista adoption would be this slow, though. So I decided to wait for a year or so until most of Vista's general problems are solved. I hoped that software and hardware vendors would start embracing Vista x64 as soon as they got the 32-bit version under control.

Today, I will focus on software compatibility. In my next post, I will blog about Vista x64 hardware compatibility.

32-bit vs. 64-bit applications

According to an article of the German print journal C’t (8/2008), 64-bit is still not a topic for most software vendors. That is, most Vista compatible applications are 32-bit. Essentially, those software vendors offering 64-bit versions, do so only because they were unable to make their 32-bit editions work on Vista x64. Manufacturers of antivirus software are a good example. Their hooks go deep into the operating system which requires playing 64-bit.

However, it is also a matter of fact that now most Vista compatible 32-bit apps work on Vista x64 as well. Actually, it is hard to find software that runs on Vista x86 but not on Vista x64. If you know of such an application feel free to leave a note below. Notice that 16-bit apps don’t work at all on Vista x64. Some older 32-bit programs have a 16-bit installer. The only way to make them work on Vista x64 is to create your own installer package. If you are unsure whether your Vista apps are 64-bit compatible, you can just test them with VMware Server or VMware Workstation. So all in all, I’d say application compatibility is not really an issue anymore.

WoW64 (Windows on Windows)

You should be aware of the fact, though, that running 32-bit apps on Vista x64 comes with a price. Vista has to perform some acrobatics to make this possible. The trick is called WoW64. Basically, it has two tasks. It switches the CPU from 64-bit mode to compatibility mode when you launch a 32-bit app. This doesn’t go at the cost of performance. If you install Vista x86 on a 64-bit CPU, it will always run in 32-bit mode.

In my opinion, more problematic is the second feature of WoW64. 32-bit programs are often dependent on 32-bit system libraries which are stored under C:\Windows\System32 on Vista x86. You’ll also find this folder on Vista x64. However, despite of its name, it only contains 64-bit libraries. Vista x64 stores 32-bit libraries in C:\Windows\SysWow64. 32-bit apps always try to load system libraries from System32. Hence, WoW64 has to redirect them to SysWow64. The same applies to some Registry hives. For example, WoW64 redirects HKLM\Software to HKLM\Software\Wow6432Node.

WoW64 is comparable to the other virtualization mechanisms in Vista which assure software compatibility with Windows XP programs. UAC and folder name changes made them necessary. Usually, these redirects work fine. However, any new complexity layer can be the cause of unforeseen problems. The importance of Vista’s virtualization mechanisms for legacy apps decrease steadily because software vendors adapt their programs to Vista. However, since you’ll be forced to run 32-bit apps on Vista x64 most of the time, you’ll be dependent on WoW64 as long as software vendors focus on Vista x86. That is, you will always have to run programs which are designed for another operating system.

Subscribe to 4sysops newsletter!

In my next post in this series, I’ll blog about the situation regarding device drivers for Vista x64.

  1. Beau 15 years ago

    The only software I have found that doesn’t work on Vista x64 is Dragon Naturally Speaking. It is a shame because DNS would actually benefit from the additional RAM…

  2. Did you ever try Vista’s speech recognition? I played a little with it, but gave up after a while. This thing does not even understand “Windows Vista”. But it is quite possible that this poor thing is just confused by my German accent. Is Dragon Naturally Speaking better?

  3. XFactorXXL 15 years ago

    This was reposted from an earlier thread for updated answers =)

    question for this topic:
    Noting what was said about the whole WoW64 thing, it may have been answered int he topic but I am still unclear, is there a performance loss when 32 bit apps run in x64?

    I’m beginning to think the only way to truly answer all my question is just to run and compare both OS’s. =P

    Hey all,

    I have a couple questions I’m finding hard to get definitive answers to on the Vista Ultimate x86 to the x64 Ed migration. My question is this:

    I do have a system that I believe to be fully x64 ready (I’ll add a breakdown at the end of the post). My only concern is what I have been hearing about this “digitally signed driver” issue. The reason for this is I run gobs of software that has it’s own “unsigned drivers” ie Virtual CD/DVD rom mounting software like MagicDisc/MagicISO as well as some other titles. Am I still going to have issues running these apps or has this been fixed by Microsoft / software developers since some of the earlier 2007 threads and posts?
    Second, as a “part-time gamer” and “media encoder/enthusiast”, how significant of a performance increase can I expect by moving to x64?

    Any insight or additional information would be greatly appreciated.

    Here is a breakdown of the system I currently use (although not the fastest is does the job =P)

    Asus M2N-E SLI mobo w/ X2 4200+
    -Cmedia CM6501 onboard audio
    2 GB Corsair Dom. 667 DDR2 (willing to upgrade)
    2 160 GB WD SATA2’s in raid Array
    2 BFG 8600GT OC’s in SLI
    2x 500GB SATA2’s for storage (addicted to ripping movies)

    here is a questionable hardware piece i run as audio IO for recording studio:
    -Creative EMU 1212M PCI pro sound card

    Thanks again and look forward to hearing from you all!

  4. Boomer 15 years ago

    I built my own system mostly for imaging & gaming, I installed ultimate x64 with 4GB of RAM all working fine and very happy with Vista. Due to the vast amount of files I have acquired over the years I decided to invest in a proper backup solution and decided to wait for the HP MediaSmart server to arrive running MS home server. It turns out that this is not compatible with x64! Nowhere on the site does it say its not compatible or even on the system requirements on the box so now my only option to keep this server was to purchase ultimate x86. I find it hard to believe that MS do not support their own x64 operating system. Now my only problem is that I cannot get 4GB of RAM working on my x86 OS.
    PS. MS One care will not work with home server!
    go figure

  5. Singh 15 years ago

    Hiya, great articals.

    “Taskbar Shuffle” is not x64 compatible (yet…) because the developer has used Delphi with restrictions to x86. He will need to learn a new lauguage/system to re-write the entire software for x64!

    It’s so far been the ONLY application to keep me using Vista x86, but now that I’ve got 4 GB of RAM, I have no choice but to reinstall the system to x64.


  6. Freddie 15 years ago

    Thanks! Great articals!
    Now I can upgrade to VISTA Ultimate 64bit.

  7. Alejandro 15 years ago

    Secway simp lite-MSN 2.2.11 settles in Vista Ultimate x64 but it does not encripta the conversations of messenger service, i’m to know to me if it is because x64 is not compatible with Vista, thanks.

  8. EDocTooR 15 years ago

    I installed Vista Ultimate 64 bit and it seems as though it still a Vista 32 machine; since, most programs to run on 2 GB of memory; why, use 64 bit OS?

    Secondly, Since I can’t return my Vista Ultimate 64 bit, and since I have XP,, how hard is it to tripple boot into Vista, XP, and “UBUNTU”?

  9. Stephen Yavorsky 15 years ago

    Dragon Naturally Speaking does not work on Vista 64-bit. Neither version 9 nor version 10. When trying to install, a message appears that the operating system is incompatible with the program. The website, as of September 2008, verifies this, and says that though the company is working on it, there is no promise as to when a Vista 64 compatible version will actually appear.

  10. Michel 15 years ago

    I use x64 because I can benefit from my 8GB to host Virtual Instruments. I ‘ve never had an issue with any sort of application.

  11. You guys should read this then…

    Dragon Naturally Speaking 9 can be installed on Vista 64 – because I’m.

    How ’bout this; Truth – Common sense is no match for natural stupidity.


  12. Gary Johnson 14 years ago

    Vista 64 software compatibility.
    Even prgrms by Intuit’s Quicken won’t run on Vista 64. Qucken admits it with no advise as to a solution for me sitting there with a broken XP cpu and new Vista 64 bit system that can’t run programs I need. MS is no help either. I would wait and buy Win 7 but how do I know prgrms will be compatible with that? I need direction.
    Gary J.

  13. Nathan L. 14 years ago

    Solution: Simple. Run Windows XP 32-bit until it is retired in August 2014. That way we can use ThreatFire, Google Desktop, OneNote Print Driver, and a slew of other things that STILL do not work on 64-bit. I will gladly sacrifice 1GB of RAM and live with greater compatibility with a HUGE library of old games, etc.

  14. Stephen 14 years ago

    Software compatibility is only one issue. Hardware compatibility is also a real problem. I had to get a new printer and new voice recorder to work with Vista-64. I found no scanner that would work, even after speaking with tech support for companies that insisted their scanner worked with Vista-64. Advertising was deceptive. Vista-64 claimed it was a better operating system, but mentioned nothing about the programs and devices that would not run on it. Programs would advertise that they run with “Vista” without ever distinguishing between 32-bit and 64-bit. // This approach seemed quite wrong.

Leave a reply

Your email address will not be published. Required fields are marked *


© 4sysops 2006 - 2023


Please ask IT administration questions in the forums. Any other messages are welcome.


Log in with your credentials


Forgot your details?

Create Account