Unable to Install dplyr Package in R Studio Windows 10

Question

I try to install dplyr package using command install.packages("dplyr"). I get following error. Could anyone identify what is the issue here? Am I missing someting?

Warning in install.packages :
  InternetOpenUrl failed: ' âˆû'
Warning in install.packages :
  InternetOpenUrl failed: ' âˆû'
Warning in install.packages :
  InternetOpenUrl failed: ' âˆû'
Warning in install.packages :
  unable to access index for repository http://cran.rstudio.com/src/contrib:
  cannot open URL 'http://cran.rstudio.com/src/contrib/PACKAGES'
Installing package into ‘C:/Users/mani/Documents/R/win-library/3.4’
(as ‘lib’ is unspecified)
Warning in install.packages :
  InternetOpenUrl failed: ' âˆû'
Warning in install.packages :
  InternetOpenUrl failed: ' âˆû'
Warning in install.packages :
  InternetOpenUrl failed: ' âˆû'
Warning in install.packages :
  unable to access index for repository http://cran.rstudio.com/src/contrib:
  cannot open URL 'http://cran.rstudio.com/src/contrib/PACKAGES'
Warning in install.packages :
  package ‘dplyr’ is not available (for R version 3.4.0)
Warning in install.packages :
  InternetOpenUrl failed: ' âˆû'
Warning in install.packages :
  InternetOpenUrl failed: ' âˆû'
Warning in install.packages :
  InternetOpenUrl failed: ' âˆû'
Warning in install.packages :
  unable to access index for repository http://cran.rstudio.com/bin/windows/contrib/3.4:
  cannot open URL 'http://cran.rstudio.com/bin/windows/contrib/3.4/PACKAGES'