If during installation of Rollup 5-v2 for Microsoft Exchange Server 2010 SP2 you receive error 80070643, it’s caused by WMF 3.0 (Windows Management Framework 3.0).
Windows Management Framework 3.0 is installed with following windows updates for Microsoft Windows 2008 or Windows 7 (KB2506146 and KB2506143)
So before installation of Rollup 5-v2 check and uninstall these KB2506146 and KB2506143 and WMF 3.0
Also remember to run installation of any Rollup with elevated privileges Run as Administrator