Home folders and UAC have very little to do with the real-world security of Windows vs. other operating systems. The reality is, even today, if you get arbitrary code execution on any operating system you are probably boned.

Even when arbitrary code is being executed, if the user has limited permissions kernel-level, a program can't screw up the whole system.

The Android NDK is reliant on this - any application in Android can perform your arbitrary code execution, and it seems to be working out alright.

The kernel is not some almighty bug free program. The question is then just whether or not the person who has gained the capacity to run code on your system knows an exploit that will give them root privileges.

The Android thing works because you aren't just running arbitrary code, you are probably running code that you got from the Android Marketplace, which was probably screened to make sure it doesn't do something bad.

How would they be screened? If you include native libraries in your APK, they're binaries, not code. They could scan the binary for API calls, but you're permitted to call dlopen() etc, so you could always hide a shared object in there and call it dynamically.

Okay, you can't screw up the whole system, but you can install a keylogger (X has got to be the most insecure windowing system out there), and you can use the system for a DDoS botnet.

Also if you use sudo or su in X, they now have root thanks to the keylogger.

And with threaded code attacks you don't even need to download an executable. You can run "script level" code by repurposing existing executable sequences.

Security is hard.

If people cared about "we did x first" as a reason why some software is better, everyone would be browsing with Opera. What matters is how well they do something now.

I can't imagine how bad the guys from Opera must be feeling, when everyone points to them as an example of a pioneer, yet nobody actually uses Opera (a startup once called me "their Opera user")...

Windows XP is still supported, and even if I wanted to run Windows 7, it's too bloated to run on fully a third of the hardware in my organization (and that's just counting x86 desktop/laptops.) Windows XP is a problem, and Microsoft hasn't solved it.

Yes, they have. The solution is called windows 7.

The only problem is people refusing to upgrade from a decade old OS.

I'm talking about machines which barely fit the minimum specs for Windows XP - I guess this is hard for you to grasp, but some people can't afford to buy a $300 netbook when they have a perfectly functional desktop from 6 years ago.

Also, we have several applications which, while they will run on Windows 7, they simply do not run well. From a business standpoint, it's really hard to justify an upgrade that results in reduced functionality in the name of security. I can clean up after malware pretty quickly - people working with outdated but business-critical applications lose hours of their days when software starts acting up because it wasn't written with a good security model in mind and it's being forced into that environment.

You can say Windows 7 solved the problem all you want, but there remain countless areas where Windows XP is required, and virtualization is not a magic bullet - networking is always tricky. And in any case, we do all that work of migration and what do we gain? Exactly what we have right now, except with hardware accelerated graphics that don't support all our hardware and some difficult to quantify reduction in malware attacks.

What sort of hardware are you running? Windows 7 runs on netbooks!

5-7 year old hardware. This is an affluent community - I know it's unusual to think about it here but some people absolutely cannot afford to upgrade. I'm talking about hardware that barely meets the minimum specs for XP.

I'm not one of them, but I see them every day. Windows 7 does not solve the Windows XP problem. (The Windows XP problem will be solved when any given computer can run Windows 7 easily.)