I have source builds on my machine that work. However, I wanted to test a plugin with the launcher installed version of the engine for another user. When it tries to install 4.10.2 it fails with error R-1368. Here is the log file from the prerequisites installer:
[03F8:2148][2016-01-28T16:41:00]i001: Burn v3.8.1128.0, Windows v6.3 (Build 9600: Service Pack 0), path: E:\UnrealLauncher\Epic Games\4.10\Engine\Extras\Redist\en-us\UE4PrereqSetup_x64.exe, cmdline: ‘’
[03F8:2148][2016-01-28T16:41:00]i000: Setting string variable ‘WixBundleLog’ to value ‘C:\cygwin64\tmp\UE4_Prerequisites_(x64)_20160128164100.log’
[03F8:2148][2016-01-28T16:41:00]i000: Setting string variable ‘WixBundleOriginalSource’ to value ‘E:\UnrealLauncher\Epic Games\4.10\Engine\Extras\Redist\en-us\UE4PrereqSetup_x64.exe’
[03F8:2148][2016-01-28T16:41:00]i000: Setting string variable ‘WixBundleName’ to value ‘UE4 Prerequisites (x64)’
[03F8:2148][2016-01-28T16:41:00]i100: Detect begin, 9 packages
[03F8:2148][2016-01-28T16:41:00]i000: Setting string variable ‘NETFRAMEWORK40’ to value ‘1’
[03F8:2148][2016-01-28T16:41:00]i000: Setting string variable ‘Netfx20Version’ to value ‘2.0.50727.4927’
[03F8:2148][2016-01-28T16:41:00]i000: Registry value not found. Key = ‘Installer\Assemblies\Global’, Value = ‘Microsoft.mshtml,Version=“7.0.3300.0”,PublicKeyToken=“b03f5f7f11d50a3a”,Culture=“neutral”,FileVersion=“7.0.3300.0”’
[03F8:2148][2016-01-28T16:41:00]i000: Setting numeric variable ‘MshtmlVersion’ to value 0
[03F8:2148][2016-01-28T16:41:00]i102: Detected related bundle: {2890ae6b-90e9-448d-b3e6-97e43c21e2fd}, type: Upgrade, scope: PerMachine, version: 1.0.13.0, operation: Downgrade
[03F8:2148][2016-01-28T16:41:00]i052: Condition ‘Netfx20Version AND (Netfx20Version >= v2.0.50727.5420)’ evaluates to false.
[03F8:2148][2016-01-28T16:41:00]i052: Condition ‘NETFRAMEWORK40’ evaluates to true.
[03F8:2148][2016-01-28T16:41:00]i103: Detected related package: {66C5838F-B854-4A55-89E6-A6138747A4DF}, scope: PerMachine, version: 1.0.0.0, language: 0 operation: MajorUpgrade
[03F8:2148][2016-01-28T16:41:00]i101: Detected package: NetFx20_32, state: Absent, cached: None
[03F8:2148][2016-01-28T16:41:00]i101: Detected package: NetFx40Redist, state: Present, cached: None
[03F8:2148][2016-01-28T16:41:00]i101: Detected package: WI45_XP_v3_X86, state: Absent, cached: None
[03F8:2148][2016-01-28T16:41:00]i101: Detected package: WI45_XP_v4_X64, state: Absent, cached: None
[03F8:2148][2016-01-28T16:41:00]i101: Detected package: Windows6.0_KB942288_v2_x86.msu, state: Absent, cached: None
[03F8:2148][2016-01-28T16:41:00]i101: Detected package: Windows6.0_KB942288_v2_x64.msu, state: Absent, cached: None
[03F8:2148][2016-01-28T16:41:00]i101: Detected package: VC140_X86, state: Absent, cached: None
[03F8:2148][2016-01-28T16:41:00]i101: Detected package: vc140_X64, state: Absent, cached: None
[03F8:2148][2016-01-28T16:41:00]i101: Detected package: PrereqSetup, state: Absent, cached: None
[03F8:2148][2016-01-28T16:41:00]i052: Condition ‘VersionNT64’ evaluates to true.
[03F8:2148][2016-01-28T16:41:00]i199: Detect complete, result: 0x0
[03F8:2984][2016-01-28T16:41:04]i000: Setting numeric variable ‘EulaAcceptCheckbox’ to value 1
[03F8:2984][2016-01-28T16:41:04]e000: Error 0x80070666: Cannot install a product when a newer version is installed.