SOLVED Random Command Prompt windows Appears...

[Bif]

Noticed this A.M. just after my laptop boots up and I sign in,it loads my desktop and then a mysterious command prompt windows appeared for about 3 seconds (not long enough for me to see what it was) and then disappeared.
I've downloaded nothing on my machine,and I've done the SFC scan as well as the check disc scan and nothing was found.I've also run Defender and Malwarebytes and she's clean...any suggestions?
Would this event show up in the log files or event viewer ..Trouble?..and if so what might I look for?

 

[Trouble]

No idea, but.....
It is likely just one of many updaters that run from Scheduled Tasks and possibly use conhost.exe or cmd.exe as part of the process.
Check your task scheduler
Start Button -> All Apps -> Windows Administrative Tools -> Task Scheduler -> Task Scheduler Library
You can have a look at the various task's "Triggers" and you'll likely seem some or many fire "at log on of any user" or "at system startup" or another preset condition.
You can look under the "Actions" tab and it may actually tell you what is firing and perhaps even what it uses as part of the process (or not).

 

[Bif]

Thank you Mr.Trouble!..no ill effect just one of those things.Will check out you suggestions.

 

[Trouble]

Nice addition to your avatar, although I might have gone with Windows 3.11 (Windows for Workgroups)