There are a few ways to find out when your Windows system was installed. For example, you can run the following command in Command Prompt window.
SystemInfo | Find /i "Install Date"
Or a PowerShell command like this:
(Get-CimInstance -Class Win32_OperatingSystem).InstallDate
But wait, that doesn’t seem to be right. The time shown in both commands is the day I upgraded my Windows 10 to the latest feature update, not it was originally installed long time ago. It seems that the InstallDate property in the System gets overwritten every time a major feature update is installed.
So how can I get the exact date and time when my Windows was originally installed?
Luckily, Windows still keeps track of the update history and it was saved in the following registry location, under the name like Source OS followed by the updated date.
HKEY_Local_MachineSystemSetup
Now, let’s use PowerShell to pull this information in a much clear way.
Get-ChildItem -Path HKLM:SystemSetupSource* |
ForEach-Object {Get-ItemProperty -Path Registry::$_} |
Select-Object ProductName, ReleaseID, CurrentBuild, @{n="Install Date"; e={([DateTime]'1/1/1970').AddSeconds($_.InstallDate)}} |
Sort-Object "Install Date"
And here we go.
According to this, my computer was originally installed on Aug 12, 2016, and it was Windows 7 Pro. It was upgraded to Windows 10 Pro on Jan 18, 2017. The last update before the current version was done on July 10, 2018. Note that all dates listed here are in UTC format.
Remember, the list of installation dates doesn’t include the latest update. You will still use the first couple commands described in this post to find out when your current Windows 10 build was installed.