It might be the problem with hosts file.
In explorer, go to tools => folder options => view. Uncheck "hide operating system protected files" and "hide extensions for known file types" and check "show hidden files and folder".
Now navigate to c:\windows\system32\drivers\etc and locate the file named hosts and open this file in notepad. Ignore the lines starting with # but check that there are no other lines than 127.0.0.1 localhost at the bottom. Report if you see other such lines.
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