Windows Phone 7.5 build 7640
| Build of Windows Phone 7 | |
 | |
| OS family | Windows NT |
|---|---|
| Version number | 7.10 |
| Build number | 7640 |
| Build revision | 0 |
| Architecture | ARM32 |
| Build lab | WM7 |
| Compiled on | 2011-05-11 |
Windows Phone 7.5 build 7640 is an internal build of Windows Phone 7.5, which was shown in an HTC Mazaa smartphone. It was documented on the Spanish website smartGSM.[1]