I am consistently getting this error with VS 2013:
Could not copy \"C:\\pagefile.sys\" to \"bin\\roslyn\\pagefile.sys\". Exceeded retry count of 10.
I removed these packages from nuget package manager since I do not use them:
Microsoft.CodeDom.Providers.DotNetCompilerPlatform
Microsoft.Net.Compilers
Now everything works.
Simply search for the process that has a handle on pagefile.sys using Sysinternals Process Explorer and kill it.
pagefile.sys