It sounds like you're looking for information on a very specific, older version of Skype for Windows 7. However, writing a full essay on a software version number is a bit unusual, as most people just want to know if it still works.
Your best bet is often Skype for Web via a modern browser like Chrome or Firefox, though this requires a relatively updated browser version. Skype Download For Windows 7 5 5
If you are still using a Windows 7 machine and need to communicate: It sounds like you're looking for information on
Search for the latest "Skype for Desktop" installer rather than version 5.5. If you are still using a Windows 7
Here is a concise breakdown of the situation regarding : The Evolution of Skype on Windows 7
Are you trying to from that specific version, or do you just need a working video call app for an older computer?
If you are trying to download and use version 5.5 today, you will likely run into several walls: