Today at my TechNet event in Jacksonville, FL I had an attendee tell me about an issue one of his customers was having with their Windows Vista laptop.  They just couldn't get the machine to browse to anything on the wireless network at the local coffee shop - which a lot of us treat it like our "remote office"  J).  He went there with his own Windows XP laptop and had no problems.  The customer had no problems on their wireless network at home and only appears to have this problem at the coffee shop.  We chatted a bit and it appeared that he had done all the right things.  I couldn't for the life of me think of what the problem might be....until... a light went on in my head and I remembered I had blogged about something similar when I had problems with a hotel connection.  I checked my blog and found I had posted Hotel Networks and Windows Vista on September 24th, 2007.

Hopefully that will fix his problem.  He said he'd be checking my blog for the answer, so if "he" is you, let me know if this is the resolution.

 

What causes this and can it be fixed or worked around?

The problem is related to the new receive window auto-tuning in Windows Vista.  Some older routers aren't able to handle this feature, so to get around this we just need to disable the autotuninglevel.  Type the following command to do that:

netsh int tcp set glo aut=dis

The command listed above is the abbreviated version, if you like typing and want to enter the full command string it's:

netsh interface tcp set global autotuninglevel=disabled

 

When you're done, don't forget to re-enable autotuning level back to normal.  This is accomplished with the following command:

netsh interface tcp set global autotuninglevel=normal

Or

netsh int tcp set glo aut=nor

For a more detailed explanation of the problem go to Steve Riley's post Windows Vista vs. hotels.