All of your old computer equipment can be disposed of via your local authority recycling facilities

See links below for more details:-

Norfolk County Council - Where are the recycling centres?

Norfolk County Council - What you can and can't take?

Some manufacturers such as Dell also offer to take back any old equipment when you need to dispose of it:-

Dell - Recycle Now

In some circumstances I may also offer to take away any old computer equipment for you, this is then repaired/refurbished and given away to local charities and good causes

IMPORTANT: Make sure your hard disk has been removed and destroyed or securely wiped before disposing of your PC