The latest version of the software doesn't run on Windows XP Service Pack 2. You will need to acquire version 6.6.0.106. The package should look this way: SkypeSetup_6.6.0.106.msi. You can obtain the application through Google Search. There are websites that offer this version for downloading since there are user who refused to upgrade to another version of Skype. You will also need to disable Automatic Updates after you install the program using the following instruction: Tools -> Options -> Advanced -> Automatic updates ->Turn off automatic updates