title: Installing Julia BinaryBuilder.jl packages on Windows 7
body: <p>I am having difficulty installing various Julia packages on my Windows 7 laptop. When trying to <code>add</code> certain packages I receive the following error:</p>
  
  <pre><code>(v1.3) pkg&gt; add MbedTLS
    Updating registry at `C:\Users\uname\.julia\registries\General`
    Updating git-repo `https://github.com/JuliaRegistries/General.git`
   Resolving package versions...
  ERROR: Unable to automatically install 'MbedTLS' from 'C:\Users\uname\.julia\packages\MbedTLS_jll\wUtL4\Artifacts.toml'
  </code></pre>
  
  <p>Several packages install happily, and I think I've narrowed it down to those that are supplied via <code>BinaryBuilder.jl</code>, such as <code>MbedTLS</code>, <code>Arpack</code>, <code>OpenSpecFun</code>. If I try to install any packages that have any such packages as a dependency I get the same error message when it hits one of these (initially encountered when I was trying to install <code>Genie</code>.</p>
  
  <p>I am using the latest Julia (1.3.1), although I encountered the same issue previously in 1.2 - I managed to fix things eventually in that case, and tried a similar approach (manually downloading and placing in packages folder) but have not been able to fix things in this instance (although I confess that my notes were a little lacking so can't be certain I'm doing the correct thing). The various packages seem to exist in <code>...\.julia\packages\</code> (although not in <code>.julia\compiled</code>), but julia complains whenever I try to <code>add</code> them to some environment.</p>
  
  <p>I don't think I understand julia's package system well enough to see quite what is going on here. I have seen other people with similar issues but not found anything yet which has worked - any help would be much appreciated!</p>