They don't. Perhaps all devs get more than one machine, but not every employee ("blue badge") gets a 2nd or more system. My sole company-issued computer is a ThinkPad.
Afaik 2 machines are almost mandatory
1. Dev machine
2. Email machine
The 2 biggest orgs inside MS are Office and Windows, devs in both of them can't have a single machine doing both the above tasks. (And VMs suck for disk based I/O, and that becomes a factor when you have multi-hour build time)
Yes, economy does impact internally at Microsoft. Thankfully, we have Hyper-V to have more than one OS in a given box. But back in the old days, two machines per person was pretty standard. I no longer work for MSFT, so not all orgs still stick to the same policy
That's really odd. I used to work under Windows Live org, and all the Ops we know have more than one machine (at minimum, a laptop and a desktop). Even the orange badge has more than one machine...
Honestly, the only blue badge that doesn't really need more than one machine is PM. Both SDE and SDET definitely need more than one to develop and test. Ops can manage a cloud with just one, but in theory, we all know that Ops has access to a ton of VMs, so I consider them as more than one machine.
When I worked in a big Windows-centric company developing hardware and software for Windows CE (mid-2002), I had two desktops, one associated with the corporate domain, where I could print and read e-mails off their Exchange server, and another, where I had administrative privileges (VS required them to attach debuggers to processes) that didn't connect to the corporate network at all.
If you develop pieces of the OS, I would assume they would give you a machine to rebuild occasionally (because you'll probably destroy it a couple times) and one to be a well-adjusted corporate citizen, reading your e-mail and filling out your paperwork.
>VS required them to attach debuggers to processes
I don't believe this is entirely true. VS will sometimes claim you need to be an admin and offer to restart as an admin, but you can click ignore in that dialog and debugging will work just fine. The one exception is if you are running as non-admin trying to attach to a higher privilege process, in which case you would need to be able to attain the same privileges as the thing you are trying to attach to, for obvious reasons.
Since it was a long time ago, I am not sure exactly what we tried and why we failed, but I can tell you we tried hard. Corporate IT didn't like us much for having computers they couldn't manage.
At minimum people get a laptop and a desktop, and quite a bit of time you see more than one desktop in offices. I haven't seen anyone in the engineering disciplines with fewer than two.
Having more than one machine is very handy for when you need to run VMs to test different versions, and not risk getting your own main machine into a bad state. If you work on services, the VM runs a local copy of the service.
Note: I'm in Ops at MSFT.