Can't Install - Error 114

Question

Hi all, 
 One of our users recently experienced a problem where they couldn't update their endpoint security. Upon uninstallation, we ran into an error where it stopped halfway through and said it couldn't find the Sophos Anti-Virus MSI. I used the Microsoft fix-it tool to rectify the issue and restarted. I've tried reinstalling Sophos, but I now get: 
 
 There was an unexpected problem with the installation of Sophos Endpoint Security and Control. Details: Unexpected product state 2 for product with code {36333618-1CE1-4EF2-8FFD-7F17394891CE}, 12/12/2016,16:58:26,Information,------------------ Found errors during installation: 114 ------------------, 12/12/2016,16:58:26,Information,------------------ Installation program finishing with code 114 ------------------, 
 
 I've been through the registry but haven't been able to find this code anywhere. The links for the registry outputs as txt files and the installation logs are below. 
 Any help with this would be greatly appreciated. 
 https://drive.google.com/file/d/0By4ouh41WsgzU3BSQ3BmdkJDYUE/view?usp=sharing 
 https://drive.google.com/open?id=0By4ouh41WsgzYmxjY2Q0eEw3eGM 
 https://drive.google.com/open?id=0By4ouh41WsgzQVNBd25EZzdCNU0

QC · Accepted Answer

Hello RobCheale, 
 used the Microsoft fix-it tool to rectify the issue well, wouldn't call that rectify . It's like throwing away your mobile just because you've misplaced the battery, digging up the .msi would better satisfy the acceptation of rectify . Anyway something didn't work as it should with the Fix-It is there are leftovers: HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Installer\UserData\S-1-5-18\Products\816333631EC12FE4F8DFF771938419EC is the key causing the error. Please delete it and try again. 
 Christian

QC · Answer

Hello RobCheale, 
 how you worked out it's not exactly me who worked it out. The general part is to know what usually causes a Unexpected product state 2 - the product keys under ... \Windows\CurrentVersion\Uninstall\ and ...\Installer\UserData\S-1-5-18\Products\ are the prime suspects. The offending \Uninstall\ product key is given in the message, under \Installer\ it's in "compressed" format though: {36333618-1CE1-4EF2-8FFD-7F17394891CE} -> the first 8 digits are reversed, 81633363 , then the next two quadruples are each reversed and appended, 816333631EC12FE4 , finally reverse third quadruple and the remaining 12 digits pairwise and append yields 816333631EC12FE4F8DFF771938419EC . [:)] 
 Christian