hy, i think everybody knows that the following plugin exists to read the OS install time
https://github.com/PluginsOCSInventory-NG/osinstall/releases
But there is an easy way to get most of the information from registry.
1. create a registry query in OCS-Inventory Server for the following key
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\InstallDate
Now every client reports this key to ocs
2. convert the unix time stamp number to a human redable date with an online unix time stamp converter
or
search with multicriteria search for all computers with this key - export the csv - use excel to convert all the numbers with the following formula
= A1 86400 + 25569
A1 contains the unix time stamp - the resulting field - for example B1 must be formated as DATE
Thats it
