If users are unable to upload new images to an announcement, it is very likely that the Announcements Images folder does not exist on the Portal Server.
1) Navigate to Module Tools > Announcements > Module Properties
2) Select "AnnouncementsImagesPath" from the dropdown list
3) The path in this list should be set to the following location: "C:\Inetpub\wwwroot\Production Portal\Modules\Announcements\Attachments\Images\". If this is not the case, change the location to match this. (Keep in mind that "Production Portal" folder may be called something else, such as "Passageways").
4) On the Portal Server, ensure that this folder actually exists. Navigate through Windows Explorer to this location. If the folder is not there, you will need to create it manually.