Most important question: What is the error? We're not all-knowing here.
It might not be VT-x related at all, Android should be x86 in a VM and expect it to act weird.
Check the Virtualbox forums for specific details.
But a bit more on the VT issue:
I got a pc (here Medion) with Aptio as well. Problem is that I have AMD cpu on this one so the comparison won't help much.
Here the BIOS reports virtualization is on, I think. If your pc is new this year/last year, than VT-x should normally be on by default.
BUT: here Speccy says virtualization is disabled as well! Be careful, it might be a false warning. I can use virtualization in Virtualbox: the tab is enabled and I don't get any errors/warnings. So VT is ON even if Spaccy says it isn't. Check multiple sources to make sure.
Actually a good place to look is the VM log: Vbox.log in the VM folder: I see in my case AMD-V is used so virtualization is enabled.
In your case for Intel you should search for VT-X because it will report it ON or OFF.
00:00:03.677075 HM: Using AMD-V implementation 2.0!
Sorry, I'm not on my Intel machine at the moment but the previous lines should tell you what you need.