I was playing around with the settings (on the Advanced tab of the Properties dialog) eg Minumum Power Consumption.  I must have changed something I shouldn't have because afterwards although my wireless connections work there is a lot of latency and a lot of variability in latency -- I see thing by pinging any internet site with ping -t:  times are typically around 300ms, which is pretty long, but frequently top 1000 and also frequently time out.

The simplest solution seems to be restoring the factory defaults. I went through the settings by hand and tried to restore them to their original values. I think I did, but the problem is still there, so I'd like to find a way to restore the full factory default settings.

Does anyone know a way to restore the factory default settings (or a document showing what they are and I can restore them manually). 

Thanks for your help