See if you have power saving options enabled. In device manager, you should see your wifi adapter listed under neworking. Right click on it and you should see some options as long as the original drivers are installed. Also make sure windows is set to max performance. If the timing is always the same, check with windows scheduler for tasks that will run at that given time, maybe something is causing this issue in the background. Most likely though, power saving stuff will engage. If you can, always use ethernet instead of wifi.