How do I prevent IIS 7.5 from caching symlink content?

Banin's solution worked for me. The issue was resolved after changing registry parameter and resetting IIS. The C# program below (you can use LINQPad to run it) will help you reproduce the issue:

using System.IO;
using System.Net;

void Main()
 {
  var virtualPath = "JunctionPoint/sample.js";
  var physicalPath = $@"C:\IISROOT\JunctionPoint\{virtualPath}";

  for (int i = 0; i < 100; i++) {   
    File.WriteAllText(physicalPath, i.ToString());

    Console.Write(i + "=");

    var client = new WebClient();
    string html = client.DownloadString($"http://localhost/{virtualPath}");
    Console.WriteLine(html);

    if (i.ToString() != html) {
      Console.WriteLine("Issue reproduced!!!");
    }
  }
}

This problem drove me nuts for like a month a while back. You have to disable IIS caching in the registry, as far as I know this isn't documented anywhere for IIS 7 but instead is an old IIS 5 trick that still works. You can either turn the below into a .reg file and import it or you can just navigate to the section and add it manually. I recommend rebooting after changing this parameter, I'm not sure if IIS picks it up after just an iisreset.

Windows Registry Editor Version 5.00

[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\InetInfo\Parameters]
"DisableMemoryCache"=dword:1

I was previously able to fix this issue on IIS7 with Banin's fix. Since then, I have moved to Windows 10 with IIS 10, and suffered the same problem again. DisableMemoryCache did not help.

I then disabled kernel caching, and for now, that seems to fix the issue (I'm sorry for the Dutch in the screenshot):