File exists in Windows Explorer and notepad, but is not accessable in my program

Question

Why does the following problem happen?

Scenario:

• Make sure that IIS is installed
• Execute "notepad %WINDIR%\System32\inetsrv\config\applicationHost.config" using admin account

Actual Result: the file is successfully opened in notepad

• Execute the following code in admin account's context:

  string filePath = @"%WINDIR%\System32\inetsrv\config\applicationHost.config";
  Console.WriteLine(File.Exists(Environment.ExpandEnvironmentVariables(filePath)));
  

Actual Result: False

Expected Result: True

Answer 1

The problem is if you are running a 32-bit application on a 64-bit OS, the .Net framework automatically redirects the request from %WINDIR%\System32 to %WINDIR%\SysWOW64.

If you change your project to target 64-bit, this will solve your problem.

You can also resolve the problem by changing System32 to sysnative, but only if you leave the application as a 32-bit app:

string filePath = @"%WINDIR%\sysnative\inetsrv\config\applicationHost.config";

Answer 2

This might be due to file system redirection. AFAIK t happens either for 32/64 bit mismatch or in case of low-privilege (UAC) processes.

I know of now way of disabling that behavior using managed APIs. You need to use http://msdn.microsoft.com/en-us/library/windows/desktop/aa365743(v=vs.85).aspx and/or be a high privilege process.

If you change your project to target 64-bit, this is likely to solve your problem.

Answer 3

I can't reproduce your result. When I run this from an administrator command line prompt, I get exists = True.

string s = @"%WINDIR%/System32\inetsrv\config\applicationHost.config";
bool exists = File.Exists(Environment.ExpandEnvironmentVariables(s));
Console.WriteLine("exists = {0}", exists);

I'm running Windows Server 2008, 64-bit. .NET 4.0.