Returned if connection to the server failed.

The connection with the server has been reset or terminated, or an incompatible SSL protocol was encountered.

The connection with the server has been reset.

The WinHTTP function failed. The desired function can be retried on the same request handle.

The request to the proxy was invalid.

A user interface or other blocking operation has been requested.

The request failed because the handle already exists.

Indicates that a required certificate is not within its validity period when verifying against the current sys

Returned when a certificate CN name does not match the passed value (equivalent to a **CERT_E_CN_NO_MATCH** er

The application is moving from a non-SSL to an SSL connection because of a redirect.

The application is moving from an SSL to an non-SSL connection because of a redirect.

The content is not entirely secure. Some of the content being viewed may have come from unsecured servers.

The application is posting and attempting to change multiple lines of text on a server that is not secure.

The application is posting data to a server that is not secure.

Returned by [**WinHttpReceiveResponse**](https://learn.microsoft.com/en-us/windows/desktop/api/Winhttp/nf-winh

Indicates that a certificate chain was processed, but terminated in a root certificate that is not trusted by

Client authorization is not set up on this computer.

The application could not start an asynchronous thread.

The function could not handle the redirection, because the scheme changed (for example, HTTP to FTP).

Another thread has a password dialog box in progress.

The dialog box should be retried.

The data being submitted to an SSL connection is being redirected to a non-SSL connection.

The request requires a CD-ROM to be inserted in the CD-ROM drive to locate the resource requested.

The requested resource requires Fortezza authentication.

The SSL certificate contains errors.

The SSL certificate was not revoked.

Indicates that revocation cannot be checked because the revocation server was offline (equivalent to **CRYPT_E

Returned by the [**HttpRequest**] object if a requested operation cannot be performed before calling the [**Op

Returned by the [**HttpRequest**] object if a requested operation cannot be performed before calling the [**Se

Returned by the [**HttpRequest**] object if a requested operation cannot be performed after calling the [**Sen

Returned by the [**HttpRequest**] object if a specified option cannot be requested after the [**Open**] method

The requested header cannot be located.

The server response cannot be parsed.

Obsolete; no longer used.

Obsolete; no longer used.

The redirection failed because either the scheme changed or all attempts made to redirect failed (default is f

Indicates that an error occurred having to do with a secure channel (equivalent to error codes that begin with

The function was unable to cache the file.

The required protocol stack is not loaded and the application cannot start WinSock.

The Internet connection has been lost.

The website or server indicated is unreachable.

The designated proxy server cannot be reached.

An error occurred executing the script code in the Proxy Auto-Configuration (PAC) file.

The PAC file cannot be downloaded. For example, the server referenced by the PAC URL may not have been reachab

Indicates that a certificate is invalid (equivalent to errors such as **CERT_E_ROLE**, **CERT_E_PATHLENCONST**

Indicates that a certificate has been revoked (equivalent to **CRYPT_E_REVOKED**).

The function failed due to a security check.

Obsolete; no longer used.

Not currently implemented.

The MS-Logoff digest header has been returned from the website.