First of all, we HIGHLY RECOMMEND you to download HD movies, as HD offers the best quality and ultimate movie experience. The only thing you need to know if your computer is capable of playing HD video content.
Basic hardware requirements for HD movies are: (you can read full requirements here)
If you're not sure about your specs bear in mind that most of the NEW desktop/laptop computers sold in the past 2 years are able to play HD movies. If you computer doesn't meet minimum specs or playback is very choppy and is not smooth, you'd try using VLC - it's very fast, FREE and does the job well. If VLC fails to play HD files than your only option is to download DVD-quality videos.
Secondly, you need to decide what format should you choose:
The answer is very simple - no matter if you're using Windows or Mac, go for MP4, as it offers the best video quality at the lowest file size.
If you have Windows: the chances are that you may not have MP4 codec installed by default. You can download VLC player to watch movies or if you're want to watch them in Windows Media Player you need to install K-Lite Codec Pack Standard. Or, you can always download good-ol' WMV files (however quality isn't as good as in MP4s).
For Mac folks: again, MP4 format is what we highly recommend. You should be able to play MP4 in QuickTime without any additional codecs. It is possible to play Windows Media Video files (WMV) on a Mac. OS X does not come with any software that can play wmv files, but there is software you can download to get the job done. Two of the most common choices for playing WMV videos on a Mac are: Flip4Mac, and VLC (both are FREE). Just follow the links for downloads and installation manuals.
Third, with both a PC and a Mac, choose the destination on your hard-drive and then click "Save." Finally, open your movie viewer, then open the file thru the movie viewer and enjoy!
Some details about Video Formats (for tech geeks):
Downloading is the only way we recommend you access these videos. Streaming the high-quality videos (HD/DVD MP4/WMV or Mobile MP4) from our site may not work, and we can not recommend it. We have provided Flash versions of our vids for streaming.
If you have downloaded one of our movies and believe it to be corrupt, the first thing you should do is delete your previously downloaded files and clear your cache and cookies or delete your temporary internet files and try downloading the file again.
If you still cannot get the movie to play for you, we encourage you to contact us right away so that we can look into and resolve the issue as soon as possible.