PSexec copyright output

There does not appear to be a way to disable it from occurring, but as a workaround you could redirect STDERR which will suppress the output,

psexec \\remotemachine command 2>nul

PsExec v2.2 comes with -nobanner option.

Or better you can do

set F1=find /v "PsExec v2.11 - Execute processes remotely"
set F2=find /v "Copyright (C) 2001-2014 Mark Russinovich"
set F3=find /v "Sysinternals - www.sysinternals.com"
set FILTER=%F1%^|%F2%^|%F3%

psexec \\remotemachine command 2>&1 | %FILTER%