What is "WinInet replay instead of Sockets" for?
WinINet uses the Microsoft interface to the internet
Starting with version 7, LoadRunner uses Sockets mode replay by default. This was also known as Turbo replay. Socket/Turbo replay utilizes its own interface to the network card. This proprietary replay engine is a lighter engine that is scalable for load testing
The older WinInet replay, which can be enabled in LoadRunner by selecting "WinInet replay instead of Sockets (Windows only)", uses the Microsoft WinInet DLL to talk to the network card. The limitations of the WinInet replay engine are that it is not scalable, nor does it support UNIX. In addition, when working with threads, the WinInet engine does not accurately emulate the modem speed and number of connections. However, The WinInet is the engine used by Internet Explorer. It supports all of the features incorporated into the Internet Explorer, and thus, WinInet replay can resolve some replay errors.