Marc,
As far as testing goes you can run the internet diagnostics function and review the log to see what the cause is. My log had 50% dropped packets, difficult security handshakes and blamed the router for not resolving the DNS. You can also turn off security
for a test. On my router I can configure guest access separately so I set up a temporary non secured SSID the problem should go away if it is driver/router based. Third you could try to get off AES security although that does cost speed.
My suggestion is to determine the maker of the tcpip chip set through device manager and update it to the most current version from the Mfg website. It might not install automatically on check for updates. Once that is done check for router firmware updates.
When the two were in sync my problem went away and the connection went much faster.
Doing all the above fixed my Windows 8.1 update issue but caused my old Roku to fail on AES, started to get slow blank screens and not authorized for Netflix. I already had a new Roku 2 so I installed the more current one and the problem went away.
Overall I think there are two basic problems in this thread resulting in the different answers.
- Some people do not want the internet connection to go down at all. The power management and TCPIP settings seem to fix that by leaving the adapter on and not allowing the connection to time out.
- There is also a driver version issue related to security protocols especially WPA2-AES that does not exist in WPA-TKIP. This seems to be fixed by driver and router firmware to get the latest standards.
Hope this helps!