Hi, I am Dave, I will help you with this.
There is a registry key left over from that uninstalled software that is causing it to still appear on the Startup tab.
Click the link below to download a small free utility that does not require installation.
https://download.sysinternals.com/files/Autorun...
When the file downloads, unzip it.
Run Autoruns64 as Administrator
Select the Logon tab at the top of Autoruns, you should be able to find the entry for that app, then right click and delete it from there.
Restart (not shut down) your PC to apply that change.