File not found with UNC path to remote server (IIS8)

Hi,

I'm using asp classic application to check for file located in the remote server (serverB).

My asp application configured in serverA. Both servers installed with IIS 8 (Windows 2012). 

[code]

DIM fso,FilePath
Set fso = CreateObject("Scripting.FileSystemObject")

FilePath="\\serverB\dc\myfile.txt"

if (fso.FileExists(FilePath)) then

   response.Write("File exist")

else

   response.Write("File does not exist")

end if

[/code]

When i run my asp application, it will show "File does not exist". 

I already added permissions for IUSR and IIS_IUSRS to the UNC shared drive.

Any idea? Thanks in advance..