No 'safe mode' option. Are you telling that after this system crash/BSOD you cannot start SQLyog at all? Porbably some file was open and got damaged with the system crash.
Did you try to uninstall and reinstall? To completely remove SQLyog from the system do this:
1) uninstall from Control Panel.
2) Delete installation folder.
3) Delete the 'SQLyog' folder in your user profile ('AppData')