followed Watso solution and also Bernardo's solution.
I have an Asus netbook 1215n with Windows 7 home premium. All the times and more or less with all solutions after the first reboot the problem was fixed.. Further reboots still the triangle with the network adapter error...
now go to Logemein Hamachi tunnelling engine... stopped and started and problem fixed until the next reboot...
At this point I tried on Properties the option to start automatically DELAYED....
wow... now it looks really fixed... just have to wait 1 minute after the boot to have it working...
Hopefully it helps many others.
I have to confirm the usefulness of delayed start. I was having these issues with hamachi myself but unlike other people I quickly realized that stopping and restarting the service gets rid of the "adapter error" exclamation very effectively. It appears that the service starts up too early and possibly conflicts with other things going on or tries to initialize stuff that hasn't yet started up. Once the service gets an adapter error, it will not recover from it until it is restarted. Delaying Hamachi's startup with the "delayed start" service option seems to now give it all the time it needs to behave properly.
Thanks for posting this solution. I was doing something a lot more annoying to fix this issue. This happens when the virtual network adapter desyncronizes with the hamachiii service, but this is a lot faster than any of the other ways I've tried to fix this, and works every time.
>>Re: Failed to connect to the network adapter. Peer is not accessible via VPN.
>>11-03-2009 08:04 PM
>> 1) Kill the process "hamachi-2.exe"
>> 2) Disable and enable the hamachi network adapter
>> 3) Start again the service "LogMeIn Hamachi 2.0 Tunneling engine" from the control panel
>> 4) Start the Hamachi client from the Start menu
One of my Hamachi clients was outdated, auto update didn't work for some reason, so I had to manually get the update from the website.
Once I got the same version of the client on both PC's it started working again!
Hope this helps at least some of you.
PS: before I noticed the version difference I also tried "all of the above" solutions, but none worked.
I'm having the exact same problem as you posted Shu. Did you ever figure this out? I would really appreciate it if you could pass along what you did to resolve the problem. I've tried the suggestions here that I can, I've tried to reset winsock, and tried to install just the hamachi network adapter driver itself and nothing works.