Get-EventLog -LogName Application -Source wininit | Select-Object -Last 1 -ExpandProperty message
This command will query the Application log with any entry whose source is "wininit" and then those objects are piped to select and expand only the "Message" property of the most recent entry.
Please note that the command above is a "one-liner" (no line break).
NOTE: I have only tried this on Windows 7 OS
