If you’re seeing high latency that’s present on a Windows machine, there’s a third-party tool which can help to determine if there’s something on the machine itself that’s causing the issue. This can be downloaded from www.resplendence.com/latencymon.
The tool will indicate specifically what on the system is causing the issue. Commonly seen causes are ‘ndis.sys’ for example. A search for the issue online will bring up a list of possible solutions, such as ’ndis.sys latency’ brings up the Microsoft solution at ndis.sys latency
The tool can be used as a starting point to troubleshooting latency issues present in a network where there are Windows machines.