윈 도 우 특정사이트에 대한 접속이 안됩니다....

호스트파일을 재설정 해보심이 어떨까요?

https://support.microsoft.com/ko-kr/help/972034/how-to-reset-the-hosts-file-back-to-the-default

위 사이트에는 윈8까지만 나와있는데 제 경우(윈도우10)에는 아래와 같이 되어있으니 참고해서 변경해보세요

# Copyright (c) Microsoft Corp.
#
# This is a sample HOSTS file used by Microsoft TCP/IP for Windows.
#
# This file contains the mappings of IP addresses to host names. Each
# entry should be kept on an individual line. The IP address should
# be placed in the first column followed by the corresponding host name.
# The IP address and the host name should be separated by at least one
# space.
#
# Additionally, comments (such as these) may be inserted on individual
# lines or following the machine name denoted by a '#' symbol.
#
#
# For example:
#      102.54.94.97     rhino.acme.com          # source server
#       38.25.63.10     x.acme.com              # x client host

# localhost name resolution is handled within DNS itself.
# 127.0.0.1       localhost