Access shared folder from application deployed in IIS - asp.net

Question

I have a problem when I try to access a file from a shared folder in a local network.
When I run the application in Visual Studio it works fine and I can download the file, but when I deploy the application to IIS, it simply doesn´t work.
I don´t understand why, cause I give full permissions to all users, including NETWORK SERVICE and IIS_USR.
I'm currently using my computer to test this. It has Windows 7 and running IIS 7.5. The shared folder I'm trying to access is on a Windows Vista installation which doesn´t have IIS installed.
The code to download file is this:
protected void button_Click(object sender, EventArgs e)
{
Response.Clear();
Response.ContentType = "application/octet-stream";
Response.AddHeader("Content-Disposition", "attachment; filename=S10.png");
Response.WriteFile(#"\\192.168.1.82\Machine\file.png");
Response.End();
}
and it gives me the following error:
Description: An unhandled exception occurred during the execution of
the current web request. Please review the stack trace for more
information about the error and where it originated in the code.
Exception Details: System.UnauthorizedAccessException: Acesso negado
ao caminho '\192.168.1.82\Machine\file.png'.
ASP.NET is not authorized to access the requested resource. Consider
granting access rights to the resource to the ASP.NET request
identity. ASP.NET has a base process identity (typically
{MACHINE}\ASPNET on IIS 5 or Network Service on IIS 6 and IIS 7, and
the configured application pool identity on IIS 7.5) that is used if
the application is not impersonating. If the application is
impersonating via , the identity will be
the anonymous user (typically IUSR_MACHINENAME) or the authenticated
request user.
To grant ASP.NET access to a file, right-click the file in Explorer,
choose "Properties" and select the Security tab. Click "Add" to add
the appropriate user or group. Highlight the ASP.NET account, and
check the boxes for the desired access.
Please someone could help me.
Thanks in advance.

Answer 1

You have given access rights on the file system (full control is overkill for this, read or modify should be fine), but you will likely find the share permissions are still at the default of read only. You need to change the share permissions.
Read this for more info.
EDIT: The reason it works ok when debugging is because it's using the account you are logged on with, not the aspnet account in VS.
Create a new app pool, running under a service account which is a member of the IIS_WPG group on the IIS server and has permissions on the share you want to write back to (remember to set the service account to password never expire). Give the IIS_WPG group Read & Execute, List Folder Contents, and Read permissions to the Web site directories. Change the web app to run in this new web pool.

Answer 2

solution 1:
You can define a domain user. Let IIS server run with this user ( through Pool identity or 'connect as'). give this user access rights on Shared folder.
Solution 2:
Add IIS server account into user group of the server that contain shared folder, Give this user access right on shared folder.

Answer 3

If the file and the Machine folder is in C Drive, then you also need to give permissions to the root folder containing this file path because C Drive is usually read/write protected as it has System Files in it.
So for example if the file is in the path C:\Machine\file.png.
Then you need to add and give relevant permissions to IIS users group to Machine Folder and not just to the file i.e., file.png.