SQLyog settings configuration disappeared missing

It happens sometimes when you forcefully shutdown computer.
Solution
If you don't find the sqlyog.ini it could be because it is stored in a hidden folder (user's 'AppData' folder) with Windows default setting.
It is/should be here (on Windows Vista or higher): {System_drive}:\Users\{user}\AppData\Roaming\SQLyog\sqlyog.ini.
To unhide the AppData folder go to control panel .. folder settings and check 'show hidden folders'.
However since SQLyog cannot display connections, the file is either not there or it is corrupted/unusable.
If you are using WIndows 7 or higher and have 'System Restore' turned on you may restore the complete folder C:\Users\Peter\AppData\Roaming\SQLyog.
Just navigate to it from Windows explorer, make a copy of the existing folder first just in case .., then right-click the folder, select 'properties',
go to 'previous vesions' tab and select a 'shadow copy' from before this happened for restore.
If you have a backup of the complete system or of your 'user profile' you may of course also restore from there.
As the sqlyog ini is user-specific it will not be found it you login to the system with another user account than what was used when it was created.