Some features that exist in older Windows Mobile phones will be missing from Windows Phone 7 at release time, including:
- No Compass - The compass feature will not be working at release time, as the compassAPI is not complete, and software programmers will not be able to access it.
- Will not run Windows Mobile 6 applications that you already invested in
- No Skype - The networking API does not give access to sockets, preventing Voice over IP applications such as Skype from operating on Windows Phone 7.
- Cant use my VPN - IPsec virtual private network (VPN) security was supported in Windows Mobile, but will not be supported in Windows Phone 7.
- No Data access via SD Card - Microsoft has decided that data access via Removable SD Card and PC Tethering, both of which were supported in Windows Mobile, will not be supported in Windows Phone 7 in the interest of data security which appeals to enterprise users.
- No Universal Inbox - There is no universal in-box to view multiple email accounts.
- No Mutitasking by third party apps - Although Windows Mobile 6.5 had full multitasking, Microsoft has decided not to allow 3rd party multitasking in Windows Phone 7
- No Background running by third party apps (e.g. F-Secure) - Windows Phone 7 will only allow one application to run in the foreground at one time, and no 3rd party apps will be allowed to run in the background. [The lack of multitasking also prevents inter-application communication between third-party apps].
- Windows Phone 7 will not support Microsoft's Windows Rights Management Services, which controls who can read and edit Office documents.
- The browser (based on the desktop version of IE 7) in Windows Phone 7 will not support Flash, Silverlight and HTML5 at launch. Though Flash has been confirmed to be coming to the platform, no such confirmation has been made for Silverlight or HTML5.
- There is no Native Development Kit (NDK), used by software developers to create native apps. Mozilla cited this as the reason it will not bring Firefox for mobile to Windows Phone 7.
- Windows Phone 7 does not have an application switcher (to switch between Microsoft applications).
- Windows Phone 7 will not have the ability to cut, copy, and paste. It will recognise telephone numbers and addresses, but Microsoft says the majority of users don't need 'cut, copy, and paste'.
- Will not have Smart dialing.