Determine process uptime

Solution 1:

You can see this with Process Explorer. In the taskbar menu select View and check Show Process Tree and the Show Lower Pane options. Right click on any column and Select Columns, now click on the Process Performance tab and check the Start Time box.

Community Update:

As mentioned in the comments, in more recent versions of the tool (currently as of 2019), the information has been relocated into the image tab of the property sheets regarding each process-tree item (Just double-click the process name, no other steps are required).

Solution 2:

This can be done using Powershell.

Run it as admin and then execute

Get-Process | select name, starttime

You will get a list of all running processes and their start times

Referenced from: http://blogs.technet.com/b/heyscriptingguy/archive/2012/11/18/powertip-use-powershell-to-easily-see-process-start-time.aspx