Creating a Tooltip that knows what platform is currently being used

Question

I have Mathematica 8 on my PC. I also have a new Mac with CDF-player, but not Mathematica. I want a Tooltip that shows one thing if running on a PC, and something different if running on a Mac. Both of the following show "MS-Windows" in the Tooltip even when using my Mac.

Tooltip["A String",
If[StringMatchQ[$Version,__~~"Windows"~~__],"MS-Windows",(* else Mac *)"Probably OS X"]
]

Tooltip["A String",
If[SystemInformation["FrontEnd","MachineType"]==="PC","MS-Windows",(* else Mac *)"Probably OS X"]
]

It will be even better if it can hande a third case where the OS is neither Windows or OS X. Can you show me how to do it?

Answer 1

I don't think the answer is related to choosing $OperatingSystem or SystemInformation as in Mr.Wizard's and F'x's answers (although both are cleaner than using $Version). I'm guessing you created your file on your PC and then opened it in your Mac. Tooltip then shows you the cached result from your PC. To make the tooltip refresh on your other machines, simply make it a Dynamic one. I would do:

Dynamic@Tooltip["A String", $OperatingSystem]

Answer 2

What if you try using SystemInformation["Kernel", "OperatingSystem"] instead of matching $Version? On my Mac, I get:

In[1]:= SystemInformation["Kernel", "OperatingSystem"]
Out[1]= "MacOSX"

Answer 3

How about using $OperatingSystem?

Typical values for $OperatingSystem are "Windows", "MacOSX" and "Unix".

$OperatingSystem

"Windows"