How to Check When Windows Was Installed on Your PC

What happens when you are done?

The Registry Editor shows the date and time your current Windows build was put in place, stored as a raw number. It takes an extra step to read, but it is a good cross-check against the other two methods. Together they give you a clear baseline for the machine’s history. You can use that to decide whether a clean install is worth doing.

Method 1Using Command Prompt

Command Prompt is the fastest method and takes a few seconds. You open it from the Start menu ⊞, type one short command, press Enter, and read the install date from the output. It works the same on Windows 11 Home and Pro, and you don’t need administrator rights.

1. Click the Start menu. The Start menu ⊞ opens, and you can start typing right away.
2. Type Command Prompt in the search 🔍 bar. Command Prompt should appear at the top of the results.
3. Select the app from the list. A black window opens with a blinking cursor. Leave it as a normal window, since you don’t need Run as administrator for this.

With the black window open and the cursor blinking, type this command and press Enter. It may take a couple of seconds to print its result.

systeminfo | find "Original Install Date"

When the command finishes, you will see a line that looks like this:

Original Install Date: 20210629200901.000000+000

Read the number as year, month, day, hour, minute and second. In this example that is 2021-06-29 at 20:09:01. Depending on the command and your regional settings, the date may instead appear in a format like a normal short date and time. Both mean the same thing.

If you want to see more details, type the following and press Enter:

systeminfo

For more details, visit the official Microsoft documentation on systeminfo.

Method 2Using PowerShell

PowerShell gives you the same answer with a single command, and it shows the date in a format that is easy to read. You right-click the Start button, open PowerShell or Terminal, and run the command. This works on both Windows 11 Home and Pro.

1. Right-click the Start button and select Terminal or PowerShell. On Windows 11 the menu usually lists Terminal. A window opens with a prompt that starts with PS.
2. Type the following command and press Enter. You can also copy it from the box below and paste it in:

(Get-CimInstance Win32_OperatingSystem).InstallDate

This command translates the raw system data into a human-readable format immediately. The result is a normal date and time, so you don't need to decode anything. The command only reads information and changes nothing on your PC.

Method 3Using the Registry Editor

The Registry Editor stores the install date as a number, so this method takes one extra step. You open the registry, browse to the right key, read the stored value, and convert it to a normal date. Only read the value. Don't edit or delete anything in the registry while you are there.

First, open Registry Editor by typing regedit in the Start menu search and pressing Enter. If Windows asks Do you want to allow this app to make changes to your device?, click Yes. The Registry Editor window opens with a folder tree on the left.

Navigate to this path. You can click through the folders in the left pane, or paste the path into the address bar at the top of the window if your version has one:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion

In the right pane, find the value named InstallDate. The number you see is in "epoch time," which counts the seconds since January 1, 1970. If the number is shown in hexadecimal, double-click the value and choose Decimal under Base to see it as a plain number, then click Cancel so nothing is changed. To make sense of it, copy that number and use an epoch converter website to turn it into a normal date.

Summary

Finding your Windows installation date is simple. You can use the Command Prompt, PowerShell, or the Registry Editor. Command Prompt and PowerShell are quicker. The registry route is handy when you want to confirm the raw value. Remember that if you upgraded your OS, the date can reflect that upgrade rather than the very first install. Also check your OS build version from time to time to make sure your system is fully up to date.