To return to the previous version of Skype with just one mouse click is unlikely, but if you dig deeper in your computer, the problem can be solved.
For example, to download the previous version of the program from the website of the developer. Or, if you have not deleted previously saved setup file, make use of them. Then clean the computer from Skype, that is completely remove it from system. To do this, click "start" in the toolbar of your computer under "control Panel" and go to "Uninstall or change a program". In Windows 7 it is located in the subdirectory "Programs and features". Open "Uninstall or change a program", locate the Skype. Click on it and select "Remove".
Another way to remove a program through the same menu "start". But in this case, you need to select "All programs", the list of which to find and mark the folder with the name Skype. Then select the action "Remove". Sometimes, however, in this case, in the menu there is no shortcut to uninstall this program. Therefore to rely only on this method is not necessary.
Then you can try to use the rollback system. To do this, click "start" in the "All programs" locate the folder "Standard". Open it and select "Service". Double click on this folder and from the opened list select "system Restore". Click on this line and perform a system rollback to the date when you upgraded Skype.
Once you remove the last version of the program, install the previous one. Run the installation file (in the format .exe) and follow the prompts. After the process is complete , open Skype and enter their logon credentials. For the convenience of the program, click "Save password". This will enable you not to waste your time getting after each run Skype your username and password.