<p>This might sound like a little bit of a crazy question, but how can I find out (hopefully via an API/registry key) the install time and date of Windows?</p>

<p>The best I can come up with so far is to look at various files in C:\Windows and try to guess... but that's not exactly a nice solution.</p>

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
.