HKEY_LOCAL_MACHINE

To fix this error manually:-
• First Uninstall skype completely.then follow the below steps..
• Start > Search > Type regedit
• Open HKEY_LOCAL_MACHINE.
• Open SOFTWARE.
• Find Skype.
• Backup files by rigth click and exporting them to another location.
• Delete the Skype folder
• Now install skype again, it will work fine.

To fix this error automatically:
Try completely uninstalling and reinstalling the latest version of Skype. If you still have issues:
1. Visit “http://support2.microsoft.com/mats/program_install_and_uninstall/” to get the automated fix-it tool from Microsoft.
2. Completely uninstall Skype from your computer.
3. Click Run Now to run the fix-it tool.
4. When the fix-it tool finishes, reinstall the latest version of Skype.

automated fix-it tool from Microsoft:- Fix problems that programs cannot be installed or uninstalled
What it fixes:-
• Corrupted registry keys on 64-bit operating systems
• Corrupted registry keys that control the update data
• Problems that prevent new programs from being installed
• Problems that prevent existing programs from being completely uninstalled or updated
• Problems that block you from uninstalling a program through the Add or Remove Programs (or Programs and Features) item in Control Panel