The -delcache task, yes, is about cache (though it wouldn't be surprising if it caused the program window to open).
The other comamnd -sevendays, also, likely could cause a window to open.
This was not at Windows sleep/wake, hibernate/wake, nor reboot/login. It was during normal operation.
As for Add/Remove programs - the individually installed programs, yes, I do see - publisher NCH, though alphabetically they appear under the individual names "Prism Video File Converter", "VideoPad Video Editor, and "WavePad Sound Editor". The NCH launcher/installer does not appear in the list of installed programs at all.