I do not know which Windows version I have running on my laptop. How do I find this out? I need to know before telephoning my service provider.
If, for some reason, you wanted to do this from a command line:
systeminfo | findstr /b /c:"OS Name"
(Reference: Find Windows Version from CMD.) It has the added bonus of showing the OS edition. For me, it produces the following:
OS Name: Microsoft Windows 8.1 Pro
This works on all versions since XP. You can produce the command prompt with Win+R followed by
cmd in the resulting dialog, as mentioned a couple times by other answers.
All versions before XP, if I remember correctly, clearly show the OS version and edition when booting up.
If you will check your edition op your Windows pc, you can right click on start button and select system.
This opens a window where you can find your spec's (specifications) of your computer. You can also use this shortcut Win icon + X.
Comment by @BenN, works this for Windows 8 and newer (this are: Windows 8, 8.1 and 10). For older OS, please check other answers.
wmic os get Caption,CSDVersion
Along with the other answers you can run this in the commandline and get an output like:
c:\>wmic os get Caption,CSDVersion /value Caption=Microsoft Windows 7 Enterprise CSDVersion=Service Pack 1
CSDVersion may not return anything and isn't strictly needed but it can be useful if you want SP.
More detail here.
If you still can't find the version, you can use the keys:(windows) + (R) to open up a prompt.
Then Type: "dxdiag" (without "") It should ask if you want to view drivers that are not signed. Click "Yes"
It should return this picture. There's also a LOT of other useful information in this tool. I've pointed out where you can find your OS info.
Click this link: Microsoft - Which Operating System
By default, Windows reports it's version to the websites you visit.
Websites designed to take this info and report it back to you exist, like the one above.