connect two BT headsets to Windows 8.1 Pro?

that is normal, only 1 headset at a time can be used

I agree. I you look in the Sound Properties, there is no way to do this at the machine / operating system.

You may be able to accomplish this with an adapter such as below, but I have never tried this.

http://how-to-fix-earbuds.blogspot.ru/2012/01/how-to-connect-two-bluetooth-headphones.html

Which model is your Toshiba notebook? does it have a mono socket?
 You also say>BT headset.<< Headphones maybe better as a headset also has a mic?
If you had 2 wireless headphones use them with a BT wireless transmitter dongle
This what I bought for my Partner who wanted to transform a wired headphones to wireless signal from his metal detector
Zelot B370 Wireless Bluetooth Headset Headphone is the brand but found these on Amazon
Then I bought a wireless transmitter BT dongle
Paired instantly with headphones. Played youtube videos and could hear it in the headphones to test the functions. Works perfect with is metal detecting as well. Should work with two headphones paired. Just turn one set off and move away to p[air the 2nd one.
Bluetooth 3.5 A2DP Stereo Audio adapter Dongle transmitter for TV speaker and Hi FI
Image only this is what came with it, usb is for charging. All you need do is press the button until the light blinks Blue and a voice will tell you it's paired.

example BT transmitter from amazon
Example two

Model  Satellite L55.  Both headsets have mics.  For $6 at Amazon it would be hard to go wrong.

I  have a USB BT xcvr.  Would it work to put it in plus the BT from the PC?  Seems like there would be no way to tell the OS to feed them both.

I searched for an A2DP unit that is USB based, and found serveral, but they all also say 3.5mm.  What's the deal with that?  They don't show a companion unit that goes in the stereo jack.

Hi,  old_mike
The A2DP unit maybe better suited to mobile devices.
Abco Tech Bluetooth Hands Free Calling & A2DP Audio Streaming Adapter
https://www.youtube.com/watch?v=DV-LBRzSWGI

What is the connections on your current headsets? USB?, and you want to convert them to 3.5?
Like this>USB AM to DC 3.5mm TRRS Adapter
3.5 mm is the plug mainly used today to send /receive audio from devices.
How they are paired refs to>>Both are paired, but only one gets sound when playing a video.
Sorry I have no idea>>USB BT xcvr.  Would it work to put it in plus the BT from the PC?


With the BT dongle the USB part is only used to connect the dongle to the USB port on the laptop for charging purposes
 Does your laptop have a 3.5 socket for headphones?
You would plug the BT dongle into the headphones jack on your Laptop
Then press the button and hold on the BT dongle it will blink, ( see the little dot above the round silver button) that blinks blue as it's pairing..or finding the signal from your wireless headphones.. pair with headphones, headphones must be on. A voice will tell you it's connected.
The BT dongle must be a transmitter
Here's some on Amazon

According to>technical specs
CONNECTIONS & EXPANSION
Interfaces VGA
HDMI
2 x USB 3.0
USB 2.0
LAN
Microphone input
Headphone output<<  no  speakers sockets?
Alternatively
Another idea is a USB  external sound card plug one head phones into that using 3.5 ear bud for example
 and the other into the Toshiba  headphones line out jack.
External Sound Cards
a couple of youtube video showing them
MMNOX USB External Sound Card Review
https://www.youtube.com/watch?v=EwNt0ujhmGM
Reasons to get an External Sound Card
https://www.youtube.com/watch?v=nda8jGYRPOY

I guess I thought the dongle was sort of a universal BT device that would permit both headsets to connect to it.  If that is the case, I'll deal with it.  Yes, the notebook has a 3.5mm headphone jack and three USB ports.  So if that will let us both connect, I'm in.  If not, wired ear plugs plus BT would be acceptable.  Failing all these, ear plugs and we each get a plug!  

My interest in BT was if there was a BT xcvr that would allow two to connect.  I just tried a USB BT plus the built in one, and both do not play.

Sorry this has taken so much time; I just hoped there was a driver patch that would permit two at once.

Time it takes doesn't matter, see if we can get this going for you before you leave old_mike  :)
I don't think you can use USB with 2 instances because of the way the a laptop is built to save space, the onboard audio is shared with the mic and headphones and builtin speakers.
Newer models have the two audio line out jacks supporting external speakers.
If you have that use it, but again they will be 3.5 sockets like on a desktop green socket audio out.
Where as with the laptop we'll have to use the headphones line out

The BT I'm using is the one I posted about in the snapshot above,  it is a BT transmitter not a receiver not for networking etc..also I'm on a desktop so cannot test it exactly for you, but I plugged it into the speaker >outside of desktop that is, it has a headphones line 3.5, paired it to the headphones I mentioned, played a video can hear it straight up.

Now I don't have two BT headphones only one,  but they should be the same model? possibly?
 I cant see why not, turn off the number 1 headphones, turn on number 2 BT headphones press the button on the BT dongle and pair it to number 2.
Now bring headphones number 1 back on and play a video or YouTube and see if you hear it in both.
Theoretically it should work like tuning into a radio station if it's at 500 hertz both headphones now paired should pickup on that frequency from the BT dongle.,
I thought the dongle was sort of a universal BT device that would permit both headsets to connect to it.<<What is your BT dongle?
Is it USB? have you paired both headphones?

 maybe a audio splitter is the way to go plug that into your headphones jack audio out and use two in ear stereo plugs wired at least a meter long >connected to this splitter
or

What type of BT dongle is the key here, is it a transmitter or is it like this>which has a headset service?
Bluetooth USB Adapter User’s Manual
http://www.mobilefun.co.uk/download/manuals/BluetoothUSBAdapter.pdf
Excuse the copy paste
Bluetooth USB Adapter User’s Manual
6.6.7 Headset Service
The Bluetooth Headset Service allows this computer to provide audio input/output for remote Bluetooth devices.
For example, if the remote device is a Bluetooth telephone, this computer’s microphone and speakers can be used as speakerphone input and output for that device.
• This computer must have a sound card, microphone, and speakers installed.
• The Bluetooth radio on both on this computer and the remote device must support audio.
• From the Windows system tray, right-click the Bluetooth icon, select Advanced Configuration > Local Services, and then double-click the Headset service.
• Set the common configuration properties of the service, and then click OK.
•
6.6.7.1 Usage Example with a Bluetooth Telephone
From the Bluetooth phone, search for devices that offer the Headset Service, then select and connect to this computer’s Headset Service.
NOTE: Individual Bluetooth phone manufacturers may use different terminology to describe the Headset Service, but the word “audio

Sorry for the delay; transferring three businesses off of one PC onto the notebook has been a big job.

I think I have made this subject more complex than needed, probably by not putting everything up on the table from the beginning.  The notebook as a 3.5mm headphone jack, and has BT built in.  I have just demonstrated that if the headphone jack is connected to ear buds, the BT stream stops, and vice versa.

So, my bottom line question is: is there a device (3.5mm dongle would be fine) that would allow two BT headsets to connect at once?  "Transmitter" sounds encouraging for that, but I cannot find any device with a manual or features list that explicitly says it can handle multiple connections.

Thanks for your patience Merete.  I have ordered the first unit from Amazon; be here on Sunday.  I read the reviews on all of them.  All had some comments of "doesn't work", "lasted a week", etc, etc, so I looked at those where the 5 stars were 10X the 1 star.

I'm pretty sure it will work just fine old_mike
Even the manual says so. ;)
Would love to hear from you as to how it went.
Those negative comments I bet they didn't read the manual and follow the recommended.
Lasting a week could indicate improper recharging
All the Best with your holiday
Merete

Merete:  TaoTronics arrived this afternoon, and works like a champion!  Many thanks for your patience.

Fantastic woo hoo. ;) thanks so much for your feedback old_mike.
 That was a fast delivery, yes with the right tools it works instantly.
Have a wonderful holiday and thankyou for trusting me and willing to give it a try, we did all the right research ,.
all the best.