The online installer needs to be able to download gigabytes of data during the install process. It won't work if your Internet isn't working reliably.
You could try downloading the full game again with a download helper that will try to preserve your dl progress when the connection is interrupted ... then resume downloading again when you find you have a good connection.
It's a large file, so it might take numerous attempts to get all of it without errors. If your ISP is unhappy with so much downloading, they may interrupt the connection frequently.
If the hard drive you mentioned is your C: drive, it looks like you have enough free space.
Out of curiosity... how much RAM does your system have? It is also recommended by forum members that your swap or page file be sized three times your amount of RAM.