Windows 7 To Break Backwards Compatibility

Everton | May 23, 2008 | View Comments

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Previous versions of Windows provided backwards compatibility with older versions of windows, making it easy for users to upgrades as their favorite programs would still work.

However, with Windows 7 Microsoft are approaching backwards compatibility differently, and Windows 7 will not be binary compatible with older versions. This won’t mean that older programs won’t run, but that virtualisation will be used to make them run. The key drivers for this are performance improvements, but also in an attempt to sidestep regulatory programs.

Vista struggles with performance because Microsoft choose to incorporate regulatory challenged features like Internet Explorer and Windows Media Player using a modular design, rather than the monolithic processes used in previous versions of windows. The greater use of componentisation led to performance issues due to the increased number of libraries within the operating system. Simply put, the more separate files your hard drive has to load, the slower your system is going to run.

Another reason why Vista runs so slowly is:

The operating system stores multiple copies of core system libraries, as each revision of a library typically adds/removes functions, and applications compiled with dynamic links to a specific version of a DLL file may call on functions not present in the currently installed library. Vista aims to solve this issue through the WinSxS collection; essentially a massive store of every differing version of libraries present on the system. That way, when an application makes a call for a dynamically linked library, Vista queries the WinSxS cache for the correct version, which is then loaded into memory. On the average system, this directory can be several gigabytes in size, with much of the code duplicated between the separate versions many times.

By not being binary compatible with previous versions of Windows and being built from the ground up, will give Windows 7 significant performance improvements. This will make it easier for developers to produce faster apps as they won’t have to worry about backwards compatibility, but it will increase the upgrade pain for users who may find that some of their existing applications will no longer work and will need upgrading.

Where do you lie on the trade-off between compatibility and speed? Do you think Microsoft are making a mistake here?

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About the Author: Everton is based in London and has worked in the internet and mobile space for over ten years now, and before that worked in corporate strategy and consulting. He has a degree in Economics from Cambridge University, and currently runs the Portal and online operations for one of the largest ISPs in the UK.He also writes for Windows 8 News, Connected Internet and One Tip A Day.

  • alesia911
    Frankly Microsoft usually throws out Os systems which are buggy and not fully tested they are always in a rush I would not aspect this to change now I am sure even with this new OS we will continue to see security updates and other updates related to problems with the operating system I have two versions of vista and on each have had to download over 2 GB of updates with more to come it is a shame that a mufti billion dollar company can not Put out a decent Product Out ,If it runs fast that is great but having to purchase programs that I like that won't run on the new system Is a big drag especially with the economy the way it is. Frankly I think Microsoft puts these programs out the way they do not just to keep up with technology but also so you have to purchase more products which make them more money that's why they stop supporting different OS systems that they put out to force you to upgrade there have been Os systems such as windows 2000 that worked well but is no longer supported by Microsoft or Microkill as some people call them. The only decent thing that Microsoft has is that they are somewhat open source and because of this there are much more programs for it than Mac's and other OS systems even though Mac is probably a better product and more sound, if it where not for the fact that there are more programs available for Microsoft than Mac and if mac had more programs for it which by the way is Macs fault for them not giving out their source code Mac would probably be the leader instead of Microsoft which is the only reason I own a PC and not a Mac Even though Macs run much better By the way any newbies may not know but the Gui which is the Graphical interface that Microsoft uses was bought Originally from Macintosh otherwise you would probably be still stuck with DOS or maybe there would be a graphical interface on windows but with the hasty releases of their OS would probably be even more buggy than the OS'S that they have put out. By the way why does Microsoft deal with a country such as India that basically does not protect underage girls from being bought for sex slaves and the Brothels Millions of Girls are Bought and sold in India all the time some as young as 8 years old for sex the Government of India does little to curb this atrocity SO WHY BILL GATES WHY?????
  • Ken
    I'm getting very antsy about upgrading to w7. The ms advisor program gives me a grossly incomplete evaluation and misses important programs and hardware that I use everyday (e.g. MS DIS2006 to name just one of many). It's going to take awhile before I decide to upgrade (if ever) which is complicated by the fact that any advice I'm able to get is so arcane that it is not understandable to someone like me with my limited knowledge. I just feel that I can't afford the risk of upgrading, only to discover afterwards that much of my soft/hardware has to jetisoned so that vendors can make more $.
  • Mick
    OK - so technology must go forward - no dispute there - but there are nearly as many home users as corporate users running Windows - we can't all afford to spend spend spend on new software every time they 'improve the operating system'. I have just pre-ordered a copy of Windows 7 - (wish I'd checked the blogs first - I wouldn't have bothered) - I will NOT be installing 7 on my laptop - it can stay in its box as far as I'm concerned

    I ran the beta from its release and found litle in the way of problems with my existing software - this made me think that Microsoft were going to make 7 MORE backwards compatible not LESS - how wrong I was - from the compatibility checker, most of my programs will now have minor issues and 4 of my most used programs (video editors) wont run at all - these ran ok in the Beta version - now it appears I have to buy at least the Pro version in order to run XP MODE - then maybe my software would work! HA!!!!
  • I own a computer repair shop and provide IT consulting to small business and home customers. I have come to find that most users that have problems perceived to be with the operating system are usually:
    - trying to use obsolete, poorly designed, or not up-to-date software and/or hardware
    - using hardware that does not meet the specifications for the OS or barely meet the minimun, however expecting premium optimum performance. Many manufactures are guilty of selling machines with specs that will make the OS appear slow out of the box.
    - using pirated and/or illegal software
    - using free, out-of-date, expired, or resource hungry antivirus.

    These issues are mostly unrelated to the Operating System itself. It is true that the small business and home market finds it hard to upgrade software every time a new OS comes out, so there is a point there.

    However, technology must move forward, we cannot stop making roads because of the inconvenience to the people on both sides of the construction. Is it possible that because I am "computer knowledgeable" I hardly ever have any problems with my personal machines or is it because I avoid using programs not written for the OS I am using, keep a "good" antivirus up to date, avoid questionable sites, keep OS updates up-to-date, and install only programs I need that my experience with XP, Vista, and now Windows 7 RC has been a pleasant one? Just a tought!
  • dains
    Hi, in response to this from Willy >>
    However, technology must move forward, we cannot stop making roads because of the inconvenience to the people on both sides of the construction.

    This isn't about the people living on the sides of the road, this is about the people DRIVING on it. The operating system must support the tools that are being used today, just as the road must support the cars being driven on it. Make a road that you can't drive your car on, and guess what? You aren't going to pay the toll to drive on it.
  • I think that it's sad what Microsoft is doing. They have gone from making simple administrator tasks increasingly difficult with multiple boundaries of mock security with Vista, to losing the marketshare of backwards compatibility with 7.

    As a network engineer, I still see Win NT, 2k Systems in the workplace, because they work and do their tasks and companies can't afford to get new code to run their machines and software. I still see 98SE machines, because there are still DOS based programs that are required by businesses for the same reason.

    It seems that Microsoft has finally forgotten their customers that aren't well financed and can't buy the bleeding edge to outfit their entire organization with the new hotness.

    Having been Microsoft certified for ten years, I am about to become Apple Certified because that is where this paradigm shift is leading to.

    So long Microsoft. I'll still be using XP as long as the hardware is out there. Because Xp runs so super fast on everything now and always will.

    Hello Apple, because your marketshare is about to increase 20 fold.
  • DONNA SHELTON
    To funny, I tried (few years back) all of the programs, money, outlook, bus mgr, access. and pocket pc None of them were  of any use. I sent them an email about KISS and tried to remind them of of why windows grew to be #1. THEY SIMPLIFIED THE COMPUTER FOR DUMMIES. Now they think everyone has the same capabilites and insit on complicating the simplest of tasks,  they have forgotten were are not all capabile of being president, yet we need the file clerk. I also agree with, if  it anit broke dont fix it. They tried with Vista no backward capable. I was going to wait and buy 3 systems with 7, but not now, I am NOT resetting up the whole office software and hardware. So I will just continue to have the 2 xp's I have ( under my desk)fixed and keep trading off, one goes down and the other one is ready! With the economy, do they really think we will update systems that inoder to work you have to retool your whole office. LOL
  • Tman
    I feel that M$ is making a good choice.  Backwards compatibility should be dropped.  Also there should be no 32 bit windows anymore, all systems are 64 bit it's a waste of time and degrades functionality trying to support old software.

    We should have an os that works for current and future hardware, streamlined for performance and includes a more robust virtual machine to run older programs.  I have used M$ virtual PC it's not bad but needs to be improved.

    I remember switching from dos to windows, I went from dos to windows 98, why?  because windows 3 was horrible, 95 was decent but 98 started to loose backwards compatibility but it still wasn't great.  Look at ME it was a dud, why?  because it was a facelifted child of 98.  Windows 2k&xp were children of nt.

    We need a new start, an os for the current hardware that dosen't try to support old hardware and programs.  People don't like the idea of buying new programs, well for the next 10 years keep the same fundemental structure and for the rest use vertual machines.  Trying to support outdated software is why we need to buy new programs, there is so much emulation and converson going on that the current os's perform porly on even the best hardware.

    I use mac's and linux, I find that mac's dont crash just get slower then hell, linux works well but once it's running well do only security updates as it's easier to re-install then do major updates.  I play games which is why I use windows, also I install then install drivers and most of the time it works fine, after 6-8 months it starts getting bogged down then it's time to backup important info and re-install. 

    I'm hoping windows 7 is beter then vista, though I had windows XP x64 and vista x64 dual booting on my machine when I first tried vista, was testing it.  3DMark 06 performance was withing 10 points between the two os's.  Looked into framerates for games I was playing, xp had slightly higher framerates (4-5fps) but was less consistant (ie fps would jump and spike) vista was more consistant with a slightly slower max framerate.  This depended on the game as well but was comon to most games.

    I've been using vista only since sp1, pre-sp1 had issues.
  • Chris
    I think Microsoft is sealing it's coffin on this one. It won't be faster and it will be worse for compatibility issues as many beta testers are already finding out. I think they should totally trash for what they have on the drawing board because it sucks! Vista Sucks! And here we go again windows 7 sucks! XP continues to prevail so they should work with what is working and continue to change and support it through new XP versions that support more than 4 gigs of ram and multi processors on 32, 64 and 128 bit platforms, yes 128 is coming sooner than you think.  I have a saying: "If it ain't broke don't fix it." And another: the KISS principle: Keep It Simple Stupid! XP was created using around 32 to 48 million lines of code. Vista uses well  over a 100 million and windows 7 I don't want to even guess! See a pattern here? People still want their old apps and games to work without buying all new software. Its starting to look like a big marketing ploy now. Sacrifice compatibility because it makes more money! I like microsoft but my next computer will be an apple or Linux machine because I don't like what they are producing anymore.
  • Compatibility wins in my place.  I have tried the Windows 7 Beta and have come to the conclusion that almost 75% of my software won't work on Windows 7.
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