Below is what steps I always do to fix almost issues related with windows installer (SQL ,VS ...) Before go details you should know path of logs file when Windows save for easier and/or investigate by yourself :
Default is :
C:\Program Files (x86)\Microsoft SQL Server\110\Setup Bootstrap\Log or C:\Program Files\Microsoft SQL Server\110\Setup Bootstrap\Log we can see one or more than one folders here: 100 for SQL2008 ,110 for SQL2012 and 120 for SQL2014 ... You should care about time/date folders was created .It's time you run setup.exe
Now go detail:
Almost issue I met is hangs / does nothing / disappear ... and cannot finish setup (hangs forever) --> you can see logs file and know why its hangs forever by yourself ,it's easy to know when you read logs :)
Step 1: Make sure your source setup is correct
Step 2: When you meet hangs / does nothing .. ,turn of programs and restart 01 time
Step 3 :Re-run setup - If still hangs ,open task manager beside and NOTE with what is new programs " pop up" and NOT disappear (In my case it hangs at ExecuteStandardTimingsWorkflow and I saw Microsoft common language run time native compiler (ngen processes) pop up and NOT appear so I End task it manual and Windows keep running setup )
Step 4: Some time programs cannot delete /remove or run some component setup so you need help it. Reading logs file and scroll end page ,you can see the last progress and if programs cannot do it you need help it .
Step 5: Taks manager and find windows installer ( msiexe processes) and some of them NOT responding and you need kill it by manual.
Step 6: Restart PC when it hangs Sometime programs need 01 restart to finish some task and it will continue automatic after restart .
It is what I always do and 99% case with install were fixed and run stably after then. Hope this helps :)