If you have not installed Service Pack 3 yet, you will not be running the current version of Skype since SP3 is a requirement:
https://support.skype.com/en/faq/FA10328/what-are-the-system-requirements-for-skype
You might be able do download and install Skype, but it will not launch and you will see a message like this:
Fatal ErrorFailed to get proc address for GetLogicalProcessorInformation (kernel32.dll)
That is because the GetLogiclProccessorInformation was introduced in SP3 (which has been available for almost 5.5 years).
Of course if the MS Answers forums would prompt for fundamental system information when a new question is asked - like 'What is your XP version and Service Pack' we would know all this already.