Microsoft Visual C++ 2010 SP1 is a library that adds more functionality to the operating system. Some programs are made using the programming language C++ and some versions will not work on your computer if you do not have a library or a script to read and interpret the instructions of the program.
Most of the times, when you install a software based on these libraries, that program will announce you and it will require to have this tool installed, otherwise will not work.
You can install it although you do not need it, it does not harm your computer.
Microsoft Visual C++ 2010 SP1 Redistributable Package is licensed as freeware for PC or laptop with Windows 32 bit and 64 bit operating system. It is in os components category and is available to all software users as a free download.