Android : Android Studio does not launch after change folder and proxy setting windows 8.1

i installed the android studio it did not launch it has error for build-21.1.1 after search : i have found solution for it ,that solution download build 21.1.1 and extract on sdk folder ,this error fixed but after that new error for launching android studio: The following SDK components were not installed: platform-tools, tools, extra-android-m2repository, sys-img-x86-addon-google_apis-google-21, extra-google-m2repository