Try oncemore to delete all Skype settings.
Quit Skype or use Windows Task Manager to kill any Skype.exe process. Go to Windows Start and in the Search/Run box type %appdata% and then press Enter or click the OK button. The Windows File Explorer will pop up. There locate a folder named “Skype”. Rename this folder to something different, e.g. Skype_old.
If you are on the latest Skype 6.5/6.6/6.7/6.9/6.10/6.11 version, then do also this:
Go to Windows Start and in the Search/Run box type %temp%\skype and then press Enter or click the OK button. Delete the DbTemp folder.
Restart Skype.
If this will still not help then try to uninstall the currently installed version and install the older 6.1.0.129 version using this msi-installer:
http://download.skype.com/msi/SkypeSetup_6.1.0.129.msi
After installing this version, make sure to disable the
Automatic updates:
Tools ->
Options ->
Advanced ->
Automatic
updates ->Turn off
automatic