[KwasiOwusu]

"Ah, sales figures. You mean the millions of copies of Windows sold to upgrade from older versions, not increasing marketshare?"

Nope.
I mean the figures for operating systems installed on the actual physical servers at the factory, before they ship.
Both IDC and Gartner use actual servers sold, and the operating systems installed on them before they ship.
Noboby will pay for Windows Server to be installed on their server, then delete it and install Linux on it.

"You mean all the copies of Linux running that aren't part of any sales figures?"

I mean actual servers and the operating systems installed on them at the factory.
Since neither Dell nor HP nor nor Hitachi, not Fujistu-Siemens, nor even IBM sell many "naked"(no operating systems installed) servers to businesses, your point about "uncounted copies of Linux" installed on servers from Mars just doesn't hold much water.

[antiRepublicrat]

I mean the figures for operating systems installed on the actual physical servers at the factory, before they ship. Both IDC and Gartner use actual servers sold, and the operating systems installed on them before they ship.

Oh, you mean like the hundreds of desktops and many servers we bought last year, all meant to replace current old Windows systems? Yes, that's increased sales, no that doesn't mean more operating Windows machines. You can expect to see a lot of this about a year or so after major Microsoft version changes, as organizations start to upgrade with new boxes after the old ones have amortized.

Noboby will pay for Windows Server to be installed on their server, then delete it and install Linux on it.

We did exactly that once. It was easier to buy all Windows machines and convert some of them to Linux because of the way the purchase agreement went. Of course at that time Microsoft prevented OEMs from shipping anything but Windows. We also installed Linux on many of the Windows machines getting replaced by a new purchase.

"uncounted copies of Linux" installed on servers from Mars

From Mars? How about web sites all over this planet?