Direct downloads for WinCC V7.0 SP3 Update 1 are generally not available as public web links because this software is a licensed commercial product. According to official Siemens support documentation, Service Packs and certain updates are considered independent products that must be ordered via DVD or through specific service agreements. Key Download & Ordering Information Ordering Status
You must already have SIMATIC WinCC V7.0 Service Pack 3 (or the ASIA variant) installed before applying this update. Download and Ordering Information Wincc 7.0 Sp3 Update 1 Download
To understand the download requirements, it is important to clarify the installation order: Direct downloads for WinCC V7