I understand that when uploading Apple live photos to my windows laptop that they will come across as a JPEG and a MOV, but I am missing several and I don't know why. I can see them on my phone but I can't see them when plug my phone into my laptop and look via explorer. Any ideas ? There are lots of them !
I would suggest that they are in iCloud. Can you tap Settings > [your name] > iCloud and check if Download and Keep Originals is checked? Here is Apple article just in case: https://support.apple.com/en-us/HT204264
If not, check it and leave the device for 3-4 hours with a robust Wi-Fi connection while photos will be loaded from the cloud (there is no progress bar). After this, check if you will see the photos.
If you still can't see them, do you use any cloud or streaming service for photos? Also, you just connect the phone to PC and open the DCIM folder, right? No iTunes or 3dparty software?