Cannot Get Installer to Work Properly

Hello, I read the previous thread about an installer problem but I am having a different one. After I download it and run the set up I get this message.

'A network error occurred while attempting to read from: C:\Users\PCMain\Downloads\PathofExileInstaller.msi'

When I try and run the game (I just double click on the icon on my desktop) I get this message

'The program can't start because OpenAL32.dll is missing from your computer. Try reinstalling the program to fix this problem'

Only problem is I have reinstalled it about a dozen times now and it still doesn't work. When I run the installer I get the first message every time. Please help! I would love to try this game out before the weekend is over! Thanks in advance.

Also I should point out I have repeatedly redownloaded the installer only to get the same messages. Also I am running Windows 7 64bit version.

Im having the same issue, I was playing it fine then suddenly this error? O.o wut do?