Im having the same issues right now:S
I got this error when manually installing the game... http://eu.battle.net/support/en/blog/4597494
Everytime Im done with the "download", i can see that the installer has crashed in the processes, meaning, its there, but never started..
I followed the "tutorial" I linked above, then all of a sudden i had to download 3gb's again..now im installing manually again...and while Im typing right now...it crashed again, and I got the same error (108)
Edit: Gonna run Blizzard Downloader
again, but not touch anything this time...Im just gonna wait it out, maybe it will start the installer after a while. My friend just said he had to wait like 30mins before the installer finally popped up, so we'll see :)
Have to download the 3gb's again....bleh