If you are facing this problem while installing Zune software for windows mobile phone on your Windows Xp sp3 PC, the problem is
Setup must stop because the required package 'Windows XP MBR Update' didn't Install.
Error code: 0x80070643
|Zune Software Installation Error 0x80070643 on Windows XP|
In this post you can solve this Zune Installation error by following the below steps.
1) At least you should have Windows Xp SP3 Operating system.
2) Download and Install Dot Net Framework 3.5, Microsoft .Net(dotnet) Framework 3.5 SP1 [Offline Version]
3) Download and Install Windows Media Player 11 on Windows XP SP3.
4) Now Install Zune 4.8 (ZunePackage)
Now the installation problem error: 0x800070643 has been solved, install zune on your windows xp PC without any error.