Foxit PDF Reader is a small alternative to Adobe Reader, so you can download it quickly.
It doesn't need any lengthy installation, so you can start to run it as soon as you can download it.
And it starts up immediately, so you don't need to wait the annoying "Welcome" screen to disappear.
Foxit PDF Reader is extreamly easy to use, just double click it to start and then click open button to open your PDF document.