Here is a small and working tutorial to install windows 7 from a bootable USB or Pendrive. These days most of them have a USB or Pendrive. So why don’t you try this trick.
Installing Windows 7 using a pendrive is very much faster than that from DVD/CD. You just need to follow some small steps to do this. You can keep this pendrive/USB drive for future installation of Windows 7.
If you are a beginner or don’t want to get messed up by typing in all commands, here is a Free Utility To Create A Bootable USB To Install Windows 7, Vista & Server 2008.