Answer 1

Use MinGw package installer on windows then install pthread on windows using the MinGw package installer now to use the pthread you can find many tutorials online when compiling type this: gcc -pthread [You're C file] -o [You're Output filename] in You're CMD

Answer 2

Check this question if it helps, it is same.
https://www.sololearn.com/Discuss/1859474/how-to-implement-multi-threading-in-c