Getting only 100Mbps performance when 1Gbps is supposed to be available

Hello everyone...

The title says it all..

I'm running

- Windows 10,
- a Dell Studio 1537 laptop PC,
- a Broadcom 1698 internal Ethernet adapter.

- My Internet modem is capable of running up to 1Gbps,
- I have a 500Mbps connection with my local ISP (with compression - up to 600Mbps actual),
- and I'm only getting 150Mbps at best with my setup,
- I have pretested my ISP conenction before this work with other devices and am getting 480Mbps over the ISP at this time of day.

It seems as if the Windows 10 driver is bottlenecking me at 100Mbps at this time with the compression from my ISP pushing me up to the tested 150Mbps, but how do I get a proper 1Gbps driver setup here? Attempts at setting up a driver from Broadcom.com have failed as Windows claims the driver I have found is incorrect.