Exactly so. Windows 7 on ARM is kind-of possible, but nowhere near practical. It would have no applications and a paucity of drivers and utilities.

Eg. Microsoft has a cross-compiler for ARM (Windows CE runs on ARM, for example) … but does Adobe? Do hardware OEMs (who write Windows drivers) have a cross-compiler?

So, what would Microsoft sue over? What would they be able to claim to license? Remember … it has to be something that Microsoft owns. Hmmmmm. I seem to be coming up awfully short here … Linux owns cross-platform, not Microsoft. Linux on ARM outnumbers Microsoft software on ARM by thousands to one or more.

No. The larger bulk of hardware drivers for Windows are written and owned by the hardware OEMs. Printer drivers is a classic example … written by the printer manufacturers, they come on a CD with the printer. They are not part of Windows per se. Drivers for a new architecture are a **HUGE** problem for Windows. The fact that Microsoft does not own significant parts of the drivers codebase is illustrated by the driver problems that Vista had, and still has for hardware that is no longer in production. It is also illustrated well by the fact that 64-bit Windows (which also requires new drivers) is quite scarce still.

>The toolchain should not be a problem

True. Microsoft does seem to have a cross-compiler for ARM.

But you missed the elephant in the room. Again this has happened.

Adobe Photoshop … not owned by Microsoft. Adobe has the code.

Likewise Flash players. Likewise for PDF viewers. Likewise for Dreamwaever. Adobe has the code for these too.

In a similar fashion … there is a long, long list of applications ffor Windows that are not part of Windows itself. Third-party applications. Microsoft does not have the code.

So … Microsoft ports Windows to ARM. Fine. It compiles and runs … but it runs Notepad, Calc, Wordpad and Paint.

Microsoft won't embed its own actual applications such as Office … Microsoft wants to charge you heaps extra for that. Adobe won't port its applications to Windows for ARM, nor will any other software vendor until there is a decent reason to do so.

How will Microsoft get such a market on a new platform? Existing x86 applications won't run. A good percentage of hardware won't have drivers. Application software vendors are going to have to do a porting effort, similar to Microsoft's own port of Windows itself. Users are going to have to re-buy these new ported copies.

Meanwhile, right there on the new ARM netbook machine as it is sold, there is a full copy of Ubuntu desktop with all applications already installed for you … at zero cost.

Exactly so. Windows 7 on ARM is kind-of possible, but nowhere near practical. It would have no applications and a paucity of drivers and utilities.

Eg. Microsoft has a cross-compiler for ARM (Windows CE runs on ARM, for example) … but does Adobe? Do hardware OEMs (who write Windows drivers) have a cross-compiler?

So, what would Microsoft sue over? What would they be able to claim to license? Remember … it has to be something that Microsoft owns. Hmmmmm. I seem to be coming up awfully short here … Linux owns cross-platform, not Microsoft. Linux on ARM outnumbers Microsoft software on ARM by thousands to one or more.

No. The larger bulk of hardware drivers for Windows are written and owned by the hardware OEMs. Printer drivers is a classic example … written by the printer manufacturers, they come on a CD with the printer. They are not part of Windows per se. Drivers for a new architecture are a **HUGE** problem for Windows. The fact that Microsoft does not own significant parts of the drivers codebase is illustrated by the driver problems that Vista had, and still has for hardware that is no longer in production. It is also illustrated well by the fact that 64-bit Windows (which also requires new drivers) is quite scarce still.

>The toolchain should not be a problem

True. Microsoft does seem to have a cross-compiler for ARM.

But you missed the elephant in the room. Again this has happened.

Adobe Photoshop … not owned by Microsoft. Adobe has the code.

Likewise Flash players. Likewise for PDF viewers. Likewise for Dreamwaever. Adobe has the code for these too.

In a similar fashion … there is a long, long list of applications ffor Windows that are not part of Windows itself. Third-party applications. Microsoft does not have the code.

So … Microsoft ports Windows to ARM. Fine. It compiles and runs … but it runs Notepad, Calc, Wordpad and Paint.

Microsoft won't embed its own actual applications such as Office … Microsoft wants to charge you heaps extra for that. Adobe won't port its applications to Windows for ARM, nor will any other software vendor until there is a decent reason to do so.

How will Microsoft get such a market on a new platform? Existing x86 applications won't run. A good percentage of hardware won't have drivers. Application software vendors are going to have to do a porting effort, similar to Microsoft's own port of Windows itself. Users are going to have to re-buy these new ported copies.

Meanwhile, right there on the new ARM netbook machine as it is sold, there is a full copy of Ubuntu desktop with all applications already installed for you … at zero cost.

And – unmentioned yet in these comments – embedded XP – -
If I was in the decision making chain – that is what I would pick to dust-off and port,
not do a refresh of CE.
Of course, they might want to change the name (XP) – so that they can announce, again,
the death of XP.

Drivers … written by OEMs. Codecs. Adobe photoshop. All sorts of applications and utilities. FOSS software such as OpenOffice, VLC and Firefox.

How are Microsoft going to get all these people to co-operate and port their stuff to Windows on ARM? To what end for them?

If Microsoft produce Windows for ARM, it will have an OS without any applications.

Most of you are looking at what it would take MS to get an ARM port working and regardless of how easy/difficult it would be technically this still needs resources internally and reasonably specialised ones When stating the “only” thing needed is driver support underplays the impact of that – remember Windows Vista!!

But back to the trend I mentioned.

Netbooks as we know had a significant impact on MS, before they got into the game there was a meteoric rise of netbooks and almost all of them not running Windows !! MS reacted and the tables have turned in terms of market share.

Now look forward …
Netbook prices are rising and whilst they wil still be very competitive against the traditional alternatives they could be the target for ARM powered netbooks as ATOM powered netbooks were for traditional Laptops.

Basically why couldn't the surge happen again for ARM powered Netbooks?
Then MS would HAVE TO respond. Now unlike the easier technical challenge of the ATOM chip it certainly won't be an overnight fix for ARM chips.

So for those that support MS lets hope they did keep backwards compatibility because lets face it if we have to rely on CE or NT the comparisons between Linux and Windows will produce a hilarous raft of laughter and glee from the open source folks.

Oh and market share could be impacted permanently

Not that this is a bad thing but worth thinking about…

No, the problem is the same one that accounts for PPC, MIPS, Alpha, Itanium, being essentially dead and x86_64 only becoming a viable port as the average machine is shipping with more RAM than the x86 port can address. Nobody ported any applications to the non x86 targets. Not even Microsoft's own apps division, hence DEC's FX!86 emulation layer to let NT/Aplha run Office… at speeds worse than a cheap Pentium of the day and everyone got the impression Alpha was crap and it died.

But one thing every other port had was the advantage of being more powerful than x86. ARM isn't, most implementations have severe RAM limits, etc. Unless Microsoft has a cross compiler chain (and I have seen no sign of one) even finding good developer workstations is going to be a challenge. And the end target is going to be little netbooks which will probably top out at $400 max. How many 3rd party applications houses are going to get excited about expending a lot of effort to capture customers they will see as 'cheap bastards?'

Any bets on whether we see Adobe port anything other than Flash and perhaps Reader? Yea like people will pony up $999 for Creative Suite on a low spec machine costing a third of that? Make the round of the key software people would be wanting Windows to be able to run and count how many would be likely to port. Unless Balmer threw a chair at em I doubt Microsoft's own apps division would bother.

And that leaves .NET as their potential saving move. Except they don't write much with it and few 3rd party shops are releasing 100% .NET products.