title: Error: "there is no package called ..." and trying to use install.packages to solve it
body: <p>The R studio I have in my university computer gives me an error when I try to download different packages, whereas when I'm with my laptop in the university server, I don't get this error. Because of this, I don't think that there is some kind of a proxy/server problem. </p>
  
  <pre><code>library(readr)
  Error in library(readr) : there is no package called 'readr'
  </code></pre>
  
  <p>I also tried to download the package using R.exe program or download other packages and it gave me the same error.</p>
  
  <p>After looking for a solution in the internet, I found this script: </p>
  
  <pre><code>install.packages('readr', dependencies = TRUE, repos='http://cran.rstudio.com/')
  </code></pre>
  
  <p>But it downloaded many different packages: <a href="https://i.stack.imgur.com/mV2Ck.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/mV2Ck.png" alt="picture"></a> </p>
  
  <p>I would like to know the reason why RStudio gives me this error and what happened when I tried to download readr package using install.packages?</p>