HI: I tried to install python3.5.1 64bit and python3.6.2 64bit on wondows, I met the same problem. Error 0x80070643: Failed to install MSI package. [2BD0:2360][2017-09-11T14:56:47]e000: Error 0x80070643: Failed to configure per-user MSI package. [2BD0:2360][2017-09-11T14:56:47]i319: Applied execute package: core_JustForMe, result: 0x80070643, restart: None [2BD0:2360][2017-09-11T14:56:47]e000: Error 0x80070643: Failed to execute MSI package.