ActiveSync 4.5 增強了 Smartphone 同PC和 Microsoft Exchange 間的安裝、協作以及連接能力。此外，這個版本還包括有一個診斷工具，可以掃描電腦和設備，并提供相關的解決方案。ActiveSync 4.5 支持 Smartphone 到桌面或 Tablet PC 的USB、藍牙和紅外連接。
• Supported Mobile Platforms: Microsoft® Windows Mobile® 5.0; Messaging and Security Feature Pack for Microsoft® Windows Mobile® 5.0; Microsoft® Windows Mobile® 2003 Second Edition; Microsoft® Windows Mobile® 2003; Microsoft® Pocket PC 2002, Microsoft® Windows® CE OS version 3.0; Microsoft® Smartphone 2002, Microsoft® Windows® CE OS version 3.0
• Microsoft® Office XP or Microsoft® Office 2003
Microsoft® Outlook® XP, or Microsoft® Outlook® 2003 messaging and collaboration clients required for synchronization to the desktop or portable computer of e-mail, calendar, contacts, tasks, and notes. (Outlook 2003 is recommended)
• Microsoft® Internet Explorer 6.0 or later (required)
• Microsoft® Systems Management Server 2.0