Lenovo All-In-One Logs Into Blank Screen Instead Of Desktop

How can I force my secondary machine to launch Desktop when I log in?

It's an old Lenovo IdeaCenter Flex which I've upgraded to W10 Home and is up-to-date.
I'm using a BT mousu with it but only have the internal keyboard to play with .
Also I have Stardock Start11 which gives me a Windows 7 style menu from the Start button
but I can't see that affecting this as I use that software on my main machine with no problems.

Can you explain what a Bluetooth Moudr is? is that a Bluetooth Mouse? You mention the keyboard, is your keyboard also wireless/BT? Try using a USB Wired Keyboard and Mouse. Try plugging the computer into an External Monitor and see if that works, then you will know if it is the AIO Monitor that is the issue.

I have diminishing eyesight (AMD) so am prone to typos that aren't caught by spellcheck. Sorry, yes Mouse and I only mention the on-screen keyboard, I think.

I tried every which way to restore a regular desktop, in vain. So I made an up-to-date thumb drive with Win 10 x64 ISO on it and did an in-place upgrade (repair) which cured the problem. I must have deleted something to cause this but what, I'm not certain.
Thanks.

Glad you sorted it.