C# – ASP.NET is not authorized to access the requested resource when accessing temp folder

my application that I have created using ASP.NET and C# uses a temporary path to store a document whilst it is read, and then deletes it after:

string path = string.Concat((Server.MapPath("~/temp/" + FileUpload1.FileName)));

Array.ForEach(Directory.GetFiles((Server.MapPath("~/temp/"))), File.Delete);

Thankyou for any help. The StockControl document is an example and could be imported from multiple computers on a network. based on the error message it looks like my file is not being uploaded and saved into the temp directory…

local path when debugging (WORKS):

C:\Users\USER\Documents\Visual Studio 2013\Projects\WebApplication5\WebApplication5\temp

the application is successfully deployed however when i attach the file and press "Import", i get displayed an error message:
Access to the path 'C:\inetpub\wwwroot\StockControl\temp\Book1.xls' is denied.

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: Access to the
path 'C:\inetpub\wwwroot\StockControl\temp\Book1.xls' is denied.

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 File
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.

Source Error:

An unhandled exception was generated during the execution of the
current web request. Information regarding the origin and location of
the exception can be identified using the exception stack trace below.