Old SSID showed up in Manage Known networks

I used to have a Netgear WNR3500 with a SSID of FROG. When FROG was around, I received a new Surface Pro 3 for work. Before I could put our corporate image (8.1ENT) on it, I had to set it up stock (Pro) to do the firmware updates to get the dock working, type cover, etc. No problems. To do that, I connected to FROG.
I then connected it to the company VPN router in my house and, using SCCM, imaged it with our corporate build. I probably connected it to FROG in that install too, but usually have it connected to the corporate VPN router via ethernet.
A month later I get a new R7000 router and name the SSID's DUCK (5Ghz) & SWAN (2.4Ghz). The SP3 has connected to DUCK. The WNR3500L was replaced. FROG was removed. Turned off. In fact, it was restored to factory stock. It's sitting in a box as we speak. Unplugged. Dead. Been that way for 3 weeks now.

YESTERDAY, I shrunk the HDD on the SP3 so that I could put 8.1 Pro on it to dual boot. Pro for personal stuff, Ent for work. Got it all working great. I noticed tonight though that I was connected to SWAN at 144mpbs. So I reconnected to DUCK to get on the 5ghz band. All was well. Then I went into Networks to forget SWAN.


That's when it got weird. In the list of known networks was FROG.


FROG hasn't been around for weeks. This Windows install has only been around for 24 hours. I went and looked again at the live list, thinking a neighbor liked FROG so took it for themselves. I wouldn't have connected to it anyway, if they were smart and put a password on it. But it wasn't there, of course.

How the heck was a SSID that no longer exists, in the known networks list?
The easy answer of course is that I'm in Ent right now, but I'm not. Trust me, they're WAY different. I am on a completely different partition too.
Any ideas? Are SSID's stored in the UEFI somehow?

You can usually flush out the old SSID's by just going into Airplane mode. If the connection will not go away, you may have to remove it through the Registry.

UEFI is just the new way that they program the Bios on computers. Nothing that you do gets saved to the bios.

The problem isn't that it won't go away. It was never supposed to show in the first place. Windows was installed weeks AFTER that router was removed.

EDIT: It just came to me. The settings were synced by my Microsoft account.