This error is famous for appearing during the installation of "repacked" video games (highly compressed games).
Below is an explanatory text covering what this error is, why it happens, and how to fix it.
Your PC lacks enough "swap" space to assist the RAM during intense decompression .
Try a different repack source. If FitGirl gives you error 7, try DODI or Xatab. Different repackers use different compression algorithms, and one may work better with your system.