When Windows Phone 7 was released in February, it was released with its SDK (which I used earlier), but a new SDK was released a few months later and included a free Visual Studio Express version in the SDK. Then the problem comes out, if the previous version of the SDK installed, you need to uninstall all, to install a new version of the SDK, this looks very easy, but once the new SDK installed, the old version of the development of the program, can not run. This requires the self to make a manual adjustment.
1. Add attribute content in \properties\wmappmanifest.xml:
<Capabilities>
<Capability Name="ID_CAP_NETWORKING" />
<Capability Name="ID_CAP_LOCATION" />
<Capability Name="ID_CAP_SENSORS" />
<Capability Name="ID_CAP_MICROPHONE" />
<Capability Name="ID_CAP_MEDIALIB" />
<Capability Name="ID_CAP_GAMERSERVICES" />
<Capability Name="ID_CAP_PHONEDIALER" />
<Capability Name="ID_CAP_PUSH_NOTIFICATION" />
<Capability Name="ID_CAP_WEBBROWSERCOMPONENT" />
</Capabilities>
2. If it does not work, it is possible that the Visual Studio 2010 version of the problem, which needs to be changed. Because the new version is specifically for Windows Phone.
3. If it does not work, then only after the reconstruction of a program, the process of migration passed.