How do I find the install time and date of Windows?

We have enough answers here but I want to put my 5 cents.

I have Windows 10 installed on 10/30/2015 and Creators Update installed on 04/14/2017 on top of my previous installation. All of the methods described in the answers before mine gives me the date of the Creators Update installation.

Original Install Date

I've managed to find few files` date of creation which matches the real (clean) installation date of my Windows 10:

  • in C:\Windows

Few C:\Windows files

  • in C:\

Few C:\ files

By the way, an easy way to get the 10 oldest (by creation) files in C:\ and C:\windows is to run these 2 commands on an administrative powershell session:

dir -Force C:\ | sort -Property creationtime  | select -Property name, creationtime -First 10
dir -Force C:\windows | sort -Property creationtime  | select -Property name, creationtime -First 10

TLDR

IMPORTANT NOTE if Windows was "installed" using a disk image both methods fail.

Method 1 works if windows haven't been upgraded to a new major version (e.g. Windows 10 to Windows 11). You execute the command systeminfo and look for a line beginning with "Original Install Date" (or something like that in your local language). You can get the same version by querying WMI and by looking at the registry. if windows was upgraded to a new major version this method unfortunately gives you the date of installation of the new major version. Here's an example to check the version by running systeminfo from PowerShell:

systeminfo | sls "original"

Method 2 This seems to work correctly even after a major update. You get the installation date by checking the creation time of the file system.ini which seems to stay untouched. e.g. with PowerShell:

 (Get-Item "C:\Windows\system.ini").CreationTime

Details

Another question eligible for a 'code-challenge': here are some source code executables to answer the problem, but they are not complete. Will you find a VBScript that anyone can execute on his/her computer, with the expected result?

systeminfo|find /i "original"

would give you the actual date... not the number of seconds ;)

But (caveat), as noted in the 2021 comments by Salman A and AutoMattTick

If Windows was updated to a newer version, this seems to give the date on which Windows was RE-installed.

As Sammy comments, find /i "install" gives more than you need. And this only works if the locale is English: It needs to match the language. For Swedish this would be "ursprungligt" and "ursprüngliches" for German.

Andy Gauge proposes in the comments:

shave 5 characters off with

systeminfo|find "Original"

In Windows PowerShell script, you could just type:

PS > $os = get-wmiobject win32_operatingsystem
PS > $os.ConvertToDateTime($os.InstallDate) -f "MM/dd/yyyy"

By using WMI (Windows Management Instrumentation)

If you do not use WMI, you must read then convert the registry value:

PS > $path = 'HKLM:\SOFTWARE\Microsoft\Windows NT\CurrentVersion'
PS > $id = get-itemproperty -path $path -name InstallDate
PS > $d = get-date -year 1970 -month 1 -day 1 -hour 0 -minute 0 -second 0
## add to hours (GMT offset)
## to get the timezone offset programatically:
## get-date -f zz
PS > ($d.AddSeconds($id.InstallDate)).ToLocalTime().AddHours((get-date -f zz)) -f "MM/dd/yyyy"

The rest of this post gives you other ways to access that same information. Pick your poison ;)

In VB.Net that would give something like:

Dim dtmInstallDate As DateTime
Dim oSearcher As New ManagementObjectSearcher("SELECT * FROM Win32_OperatingSystem")
For Each oMgmtObj As ManagementObject In oSearcher.Get
    dtmInstallDate =
        ManagementDateTimeConverter.ToDateTime(CStr(oMgmtO bj("InstallDate")))
Next

In Autoit (a Windows scripting language), that would be:

;Windows Install Date
;
$readreg = RegRead("HKLM\SOFTWARE\MICROSOFT\WINDOWS NT\CURRENTVERSION\", "InstallDate")
$sNewDate = _DateAdd( 's',$readreg, "1970/01/01 00:00:00")
MsgBox( 4096, "", "Date: " & $sNewDate )
Exit

In Delphy 7, that would go as:

Function GetInstallDate: String;
Var
  di: longint;
  buf: Array [ 0..3 ] Of byte;
Begin
  Result := 'Unknown';
  With TRegistry.Create Do
  Begin
    RootKey := HKEY_LOCAL_MACHINE;
    LazyWrite := True;
    OpenKey ( '\SOFTWARE\Microsoft\Windows NT\CurrentVersion', False );
    di := readbinarydata ( 'InstallDate', buf, sizeof ( buf ) );
//    Result := DateTimeToStr ( FileDateToDateTime ( buf [ 0 ] + buf [ 1 ] * 256 + buf [ 2 ] * 65535 + buf [ 3 ] * 16777216 ) );
showMessage(inttostr(di));
    Free;
  End;
End;

As an alternative, CoastN proposes in the comments:

As the system.ini-file stays untouched in a typical windows deployment, you can actually get the install-date by using the following oneliner:

(PowerShell): (Get-Item "C:\Windows\system.ini").CreationTime

In regedit.exe go to:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\InstallDate

It's given as the number of seconds since January 1, 1970. (Note: for Windows 10, this date will be when the last feature update was installed, not the original install date.)

To convert that number into a readable date/time just paste the decimal value in the field "UNIX TimeStamp:" of this Unix Time Conversion online tool.

Tags:

Windows

Installation

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