tl;dr

글이 너무 길어서 안 읽었다는 뜻

Of course, everybody who uses eclipse on windows has hit this age old bug at one point of another - documented here - but for those who aren't familiar, the TL;DR is that you get two taskbar icons for eclipse because the eclipse launcher (eclipse.exe) and the eclipse workspace (JVM) are two separate processes and you can't pin the workspace process.