Classic ASP errors with current identity does not have write access to c:\windows\microsoft.net\framework\v4.0.30319\temporary ASP.NET files

For a Classic ASP site, that path usually points to a permissions problem on a temporary folder used by the worker process or impersonated identity, not necessarily to actual .NET code inside the ASP pages.

Try this end-to-end path:

1. Identify which identity is actually failing
   • Use Process Monitor or FileMon and reproduce the error.
   • Filter for w3wp.exe and look for ACCESS DENIED entries.
   • This confirms whether the failing identity is the Application Pool identity, IUSR, NETWORK SERVICE, or an impersonated user.
2. Check the Application Pool identity and profile behavior
   • In IIS Manager, open Application Pools.
   • Select the pool used by the Classic ASP site.
   • Open Advanced Settings.
   • Check Identity and Load User Profile.
   • loadUserProfile is false by default. If profile loading is involved, the temp location used by the process can change.
3. Grant permissions to the correct temp location Based on the identity and profile behavior, make sure the failing identity has write access to the temp folder it is actually using:
   • %SystemDrive%\Windows\Temp
   • or %SystemDrive%\Windows\ServiceProfiles\NetworkService\AppData\Local\Temp
   • or the Temporary ASP.NET Files location reported in the error
   For Jet/Access scenarios, the temp folder must allow the effective identity to create temporary files. For ASP.NET temporary folders, the process identity needs at least the required NTFS permissions; Microsoft guidance shows adding Modify access for the process identity on application content and temporary locations.
4. If impersonation is enabled, test without it
   • If the site or related configuration is impersonating a user, the request may be running under that user instead of the app pool identity.
   • In ASP.NET scenarios, impersonation can be configured in Web.config with:

          <identity impersonate="true" userName="<supplied username>" password="<supplied password>" />
     

   • If impersonation is in effect, the impersonated account must have NTFS permissions on the temp folder.
   • If possible, test with impersonation disabled so requests run consistently under the Application Pool identity.
5. Use a safe troubleshooting test on the app pool identity
   • As a troubleshooting step only, temporarily change the IIS App Pool identity to a highly privileged account such as Local System.
   • If the site starts working, that confirms the root cause is missing NTFS permissions for the normal process identity.
   • Do not leave it configured that way as a solution.
6. Check IIS logs and status codes
   • Review IIS logs for 401.x or 500 errors.
   • A 401.3 indicates unauthorized access due to ACLs on a resource, which is consistent with missing NTFS permissions.
   • If the browser only shows a generic 500 Internal Server Error, disable friendly HTTP errors and also check Event Viewer for more detail.
7. If the error specifically references Temporary ASP.NET Files
   • Create or use a dedicated temp folder for the site if needed.
   • Grant only the site’s process identity Modify access to that folder.
   • This can help isolate the site from shared temp-folder permission issues.

Since permissions were already granted to C:\Windows\Temp, the next likely issue is that the failing request is using a different identity or a different temp path than expected. The fastest way forward is to capture the exact ACCESS DENIED entry for w3wp.exe, then align NTFS permissions on that specific folder for that specific identity.

• Using Classic ASP with Microsoft Access Databases on IIS
• Permissions to connect to a remote Access database from ASP.NET
• Troubleshooting common permissions and security-related issues in ASP.NET
• ASP.NET Partial Trust does not guarantee application isolation
• Use Failed Request Tracing to troubleshoot Classic ASP errors