As Nuno indicates in his comment, the error sounds like your drive mapping is not available for the user which the Deployer is running under. Since your indicate you use an HTTP Deployer, its web application is running under a service account identity (check the app pool identity) which most likely doesn't have access to the drive mapping you created.

You might want to try to login as that user and create a persistant drive mapping, however persistent drive mappings are only restored on an interactive logon, which services typically don't perform, so this still might not solve your problem (unless you keep that user logged in). See also: http://stackoverflow.com/questions/182750/map-a-network-drive-to-be-used-by-a-service

You might have more luck using a UNC path in your cd_storage_conf.xml, although then you can't enter any credentials. The path mapping is intended for local storage only, so perhaps it is an option to move the entire Deployer to Azure?

As Nuno indicates in his comment, the error sounds like your drive mapping is not available for the user which the Deployer is running under. Since your indicate you use an HTTP Deployer, its web application is running under a service account identity (check the app pool identity) which most likely doesn't have access to the drive mapping you created.

You might want to try to login as that user and create a persistant drive mapping, however persistent drive mappings are only restored on an interactive logon, which services typically don't perform, so this still might not solve your problem (unless you keep that user logged in). See also: https://stackoverflow.com/questions/182750/map-a-network-drive-to-be-used-by-a-service

You might have more luck using a UNC path in your cd_storage_conf.xml, although then you can't enter any credentials. The path mapping is intended for local storage only, so perhaps it is an option to move the entire Deployer to Azure?