Today when I was trying to install the SCCM Client on a system and was getting an error code of 0x80070641. It was failing trying to install vcredist_x86.exe with an error code of 1601 – here is the log entry for the error.
File 'C:\Windows\ccmsetup\vcredist_x86.exe' returned failure exit code 1601. Fail the installation. ccmsetup 5/9/2013 5:41:23 PM 2688 (0x0A80)
InstallFromManifest failed 0x80070641 ccmsetup 5/9/2013 5:41:23 PM 2688 (0x0A80)
In my case the Windows Installer service was not running. so I found this article and was able to resolve this issue by using Method 2 by reregistering msiexec
Click Start, click Run, type msiexec /regserver in the Open box, and then click OK.
I did not have to run it from safe mode as the article suggests but this may be required in some cases