How to tell when Windows was installed on a computer

This post shows students and new users steps to find out the date and time Windows was installed on a computer. There are times when you’ll want to know the date and time Windows was installed on a computer, and when that come comes, you can reference this post.

There are few ways one can determine the date and time Windows was installed on a computer. If you want to know how old a computer is or if Windows has been reinstalled, check the installed date.

One thing to know is that the installed date may not be accurate. That’s because, If you’ve upgraded to a newer version of Windows (e.g., upgraded Windows 10 to Windows 11) the original install date shown is the date of the upgrade.

You see how this can be misleading since the original installed date has been changed to the date when you upgraded.

Anyways, this might be something you may want to know, and if you do, know that it’s there when you wish to find out Windows installed date.

How to know the date Windows was installed?

If you want to know how old you computer is, check Windows installed date. It will tell you when Windows was installed or upgraded to a new version.

First, click on the Start menu, then search for Command Prompt. Under Best match, select the Command Prompt app as shown below.

When the command prompt app opens, type the commands below and press Enter.

systeminfo|find /i "original"

The result should be something similar to the one below.

Original Install Date:     6/29/2021, 8:09:01 PM

Alternatively, type in the commands below to show you the installed date.


The command should output something similar to the lines below:

OS Build Type: Multiprocessor Free
Registered Owner: Richard
Registered Organization:Product ID: 00329-10280-00000-AA805
Original Install Date: 6/29/2021, 8:09:01 PM
System Boot Time: 11/18/2021, 3:29:03 PM
System Manufacturer: innotek GmbH

How to find Windows installed date via registry

You can also find the date and time Windows was installed or upgrade from Windows registry.

First, open Windows Registry Editor.

The browse to the path below.

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\

Once in the folder above, locate the “InstallDate” key. Select Decimal to get the decimal value, which is the date in epoch time. Go to the site below to convert to use epoch converter to convert that value into a readable date and time.

That should do it!


This post showed you how to tell the date and time Windows was installed. If you find any error above or have something to add, please use the comment form below.

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