Steps I took to resolve this :
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
I didn't need to uninstall/reinstall Hamachi neither to rollback its version, though it may help to clean house after uninstalling, should there be multiple examples of Hamachi taking up the registry. Regedit seek and destroy of these entries has been mentioned here to help.
I suppose there are some issue related to hibernation (I'm on Windows Vista), but that's a different discussion.
Thank you Bernardo.
The steps above resolved the Hamachi "Failed to connect to the network adapter" issue.
I too suspect hibernation to be involved. FWIW, this was on Windows 7.
If you don't mind I'll answer to my own question and all the others still waiting for the fix.
Had to gather all the messages from the two related threads and guess the way, step-by-step
1. Uinstall Hamachi Adapter from Device Manager
2. Uninstall Hamachi 2 (leave settings checkbox clean)
4. See if Hamachi configuration folder is still there if not copy back the folder
5. Run the installer from website and it should detect your original settings and recreate adapter as well
hey guys , i had the exect problem , since i upgraded my hamachi to a newer version it made me a tunnul problem isuue with a yellow triangle next to him in the progrem .
now every time i tried to install the hamachi it stuck in the installtion in the part of Installing Network driver .. and its just stuck .
i have alot of network adapters in my device menger , i tried to uninstall but everyone of them told me that "failed to uninstall the device. The device may be required to boot up the computer" ..
i have alot of problem . somebody can help ?