There is a scheme called Home Access whereby low income families can get free computer, internet and support for a year. It hasn't been well publicised and I can't find a working link about it on here.
Check if you are eligible here:http://www.homeaccess.org.uk/Are-you-eligible/
Home Access is a government drive that helps low-income families who currently lack access to a computer and/or internet to get online at home.
The programme is aimed at those that need it most. If you are a low-income family in receipt of certain benefits you could qualify for a grant to buy a computer and/or a minimum of one years internet access.