In the second of the BBC's Broadband Nation reports, BBC News business correspondent Rory Cellan-Jones hits the road to help some net users tackle the problems they are having with their fast net connections.
Many find their broadband speed is variable
It is becoming a mass market product but for many of the 11 million households which have it, broadband is proving a big headache.
A combination of fiendishly complicated instructions, poor customer service and unexplained outages are giving the broadband industry a dismal reputation.
We set out to solve just a few broadband nightmares with an expert. Andrew Ferguson runs adslguide.org, a website where hundreds of people come to discuss what's good and bad about their broadband service.
We took Andrew for a walk around High Wycombe, a Buckinghamshire town which has generated a cluster of complaints to his site.
The local BT exchange now plays host to half a dozen rival telecoms services. This process, known as "unbundling", allows them to offer broadband lines but has also caused some hitches for customers who sign up.
Our first stop is at the home of Safina Younis, who has the most basic problem - she can't get broadband at all.
She first applied in November 2005 with one net provider, then after three months and a number of different modems, switched to another company.
Both firms said there might be a problem with her phone lines - but neither would send someone out to have a look. "I told them I was willing to pay for an engineer to visit," Safina explains to our net guru, "but they said they couldn't do that."
Andrew says there does not appear to be anything wrong with her phone line - but there's little he can do.
Broadband has become hugely popular very quickly
"Safina really needs a visit from an engineer," he says. "I think arranging these home visits has become harder to do since broadband really took off."
Safina is now trying to switch to a third provider and hoping for better luck.
Our next stop produces a better result. Sam Aboud lives in a village some way from the exchange.
He's an experienced broadband user who works in a video game shop but he has two problems: "Every night when I get home at about 6pm, the internet connection keeps cutting out - perhaps because everyone else is logging on. Plus I'm getting nothing like the speed I expected."
Sam thinks he's got an eight megabits per second (Mbps) service - but when Andrew plugs his own laptop into the line and runs a speedtest, it comes out at about 1.5Mbps.
The drop-out problems turn out to be nothing to do with the volume of traffic but an issue with way Sam's set up his own equipment.
Andrew makes a few quick changes and soon it's working fine. And when Sam rings his provider, it confirms that he is still in a queue for an upgrade to 8Mbps which he should get in a few weeks.
As night falls we arrive at the home of Karen Ashby. Her broadband had been working fine for a year until she came back from a holiday in August to find she had been "upgraded" to an 8Mbps service.
More than 11 million UK households have broadband
The result was that her internet access was both intermittent and incredibly slow. As Andrew gets to work it becomes clear how bad the service is, crashing time after time, with speeds going as low as 128Kbps.
His conclusion is that her phone line just isn't good enough to sustain an 8Mbps service.
Andrew's advice is that Karen she should either arrange to revert to a slower service or get a phone engineer in to upgrade the line.
But, miraculously, a few days later Karen rings to say the few adjustments our broadband doctor made seem to have made a big difference - her connection is now working smoothly at about 1Mbps.
So what's Andrew's conclusion about broadband customer service? "If the problem is intermittent, people are simply told to live with it - and if it doesn't work at all it can take ages for someone to visit."
And the biggest challenge? "Simply getting someone at the provider to talk to you."
A series of reports on Broadband Nation will be shown on BBC One's Six O'Clock News this week.