Films at your fingertips: A guide to downloading and watching movies on your computer

For many people, the notion of calling a video store to rent a film is but a distant memory. More and more of us are opting to order our rentals by post, use on-demand services on satellite or cable TV – or, more recently, rent or download films over the internet.

Watching a film on the web was once complicated and time-consuming – and the picture quality was awful. The good news is that things are changing, thanks to faster broadband speeds and improvements in home computers.

In the US, the market for downloading films is huge; there are signs that the UK market is picking up, too. In the last 12 months, nearly a quarter of Britons have downloaded a film from the internet, according to the price comparison service Uswitch.com, which also found that the average UK broadband user is already spending 30 minutes a week downloading films.

The future success of downloading films is likely to be linked to viewers' ability to hook their computers up to their TV sets – or to their having a television that can receive internet through a set-top box. That said, at present, around half the people in the UK can already watch TV on their computers in some way.

If you want to watch films on your computer, "a newer model with a large memory helps", says Rob Andrews, of the digital media analysis site PaidContent:UK. "You'll also need a large hard drive, as some films will take up a lot of space."

The computer also needs to be running a fairly recent operating system – the equivalent of at least Windows XP – and must have a media player installed, such as QuickTime. A broadband connection is also key, as the file sizes are so big that if you try to do it over dial-up, "it could take days," says Andrews.

Despite the advances in broadband, there is still some resistance to downloading films online, according to Jason Lloyd from price comparison service Moneysupermarket.com. "People are still put off by the amount of data required to download a movie," he says. "A broadcast feature film can be anything up to 2GB of data, which is not only a huge amount of data eating into your download capacity, but if you have a slow broadband connection, it could take ages."

According to Lloyd, if you are on a 2Mb connection, it could take between four and eight hours to download a film of 500Mb, while for those with an 8Mb connection, it will take between 30 minutes and two hours. "I would recommend that anyone who wants to download films opts for a high-speed connection of 16Mb or faster," he says. "Providers such as Be Broadband, Virgin Media and Sky Broadband all offer this."

At the same time, Steve Weller from Uswitch warns that, although high-speed internet users may think that they are signing up to "unlimited" deals, they may be subject to a "fair usage policy", which could mean them being cut off or charged a fee if they use the service " excessively" – especially during peak times.

Once you've got broadband installed, you can take your pick of the film-downloading sites, which include Lovefilm, 4 On Demand (4OD), Empire Movies, Wippit, Vizumi and Sky Anytime.

"Many of the sites offer customers the option of either renting the film for a set period of up to seven days, say, or buying the film outright," says Weller. "The Hollywood blockbuster King Kong was available online at the same time as the DVD release; the high-quality version was 5GB in size."

Lovefilm, for example, has more than 2,500 titles, with rental prices starting from 79p for a short film and from £1.99 to £2.99 for a full-length feature. Channel 4's 4OD service offers 2,500 hours of programming, and charges up to £1.99 to rent a film; it offers TV series as well. At Vizumi.com, it will cost you up to £2.99 to rent a film, and Wippit offers a range of movies from 99p, most of which are available as permanent downloads for £15.99.

The services will require you to download and install a special piece of software before you can start downloading a film. With many services, this sits on your desktop and manages the download process.

"The UK film download market is still in its infancy," says Lloyd. "But some specialists predict it will be obsolete before it gets started. Forrester Research predict that the film downloading market will decrease as more and more people move to video-on-demand services such as Tiscali, Virgin Media and BT Vision, which download more quickly and generate better revenues."

Tiscali, for example, launched its film download service, Movies Now, in May. With this online video-on-demand service, you can choose to "rent" or download films to own from 99p; renting the latest blockbuster films at "super high" quality will run you up to £3.49. You get the downloaded film for seven days, and once playback is started, you can watch the film as many times as you like within 24 or 48 hours.

"When you look at the time it takes to download a film online, you soon see where video-on-demand services come into their own," says Lloyd. "Not only is downloading from a video-on-demand service a lot quicker, it's also cheaper. Tiscali's new TV-on-demand service is far easier than going to the video shop or even downloading via a film download website. "

While there are plenty of legal film download websites around, there is also a lot of illegal activity still going on. Uswitch findings suggest that a fifth of us have downloaded illegally at least once.

"Movies get on to these channels if people copy a DVD, put it on to their computer, and share a file online," says Andrews. " Alternatively, it's a case of people videotaping the movie and putting it online."

While the industry is working to crack down on this, Lloyd warns that piracy of films via peer-to-peer networks, is another problem that could prevent growth of the online movie download market. "It's not hard to type 'peer to peer' into Google to find dozens of sites that offer users the ability to download films for free – and in some cases, films that haven't been released yet," he says.

Keith Reed from Trend Micro, an internet security company, warns that because peer-to-peer networks do not actually host any movies but rely instead on users "sharing" their own files, there is no control over content. "Files on peer-to-peer networks can contain code that can spawn a string of pop-ups and install adware, or worse, lie dormant, recording all of your private information, such as credit cards," he says. "I'd urge people to download films safely by using a reputable source."

Save on utility bills with The Independent's price comparison service