HTC Arrive which was launched in March this year, with a sliding qwerty keyboard and a 1GHz processor running Microsoft’s Windows Phone 7, has received a Windows Phone 7.5 update which can be seen on Sprint’s site which was just updated.
Sprint’s updated page does not mention Mango but the additional features mentioned clearly shows that it is Mango. If you got HTC Arrive then your phone should show an update, if it does not then you can check for an update by going to settings and tapping on Phone and then update. If you still don’t get the update then you can wait and try again. Once you get the update you can connect your phone to the PC, switch on Zune, go to settings, phone and then update. If you own the HTC Arrive and have updated your device to Windows Phone 7.5 then tell us what you think about it in our comments section.
You can checkout the support page over here