“The connection has been lost. Attempting to reconnect to your session…” had almost made me scrap Vista on my home PC. Ever since my hard drive died and I committed to Vista, I’ve received this error message when attempting to access my Windows 2003 SBS Server. I’ve had no problems accessing Windows XP based machines, but I experienced the exact same issue using Terminals from this machine.
I was sick of having to break out my XP laptop to administer my work network from home, so I decided today was the day to fix this problem. I searched and Googled and read the entire Vista Remote Desktop Connection Authentication FAQ, but did not find the answer.
I hoped setting the AuthenticationLevelOverride registry key would do it, but that didn’t make a difference.
netsh interface tcp set global autotuninglevel=disabled
This disabled Vista’s TCP/IP autotuning feature. I didn’t even have to reboot, Remote Desktop has worked great ever since I made this change. No more problems, not even once.
If for some reason you want to re-enable TCP/IP auto tuning, the command is:
netsh interface tcp set global autotuninglevel=normal
Check out my other post concerning problems with Vista’s auto tuning and Microsoft Outlook 2007’s cached mode.