The Assistant

Quarterfinalist - Amazon Breakthrough Novel Award, 2011.
Agoraphobic Stuart Watson hasn't left his flat for two years, relying on the internet, his phone and a credit card for all contact with the outside world. But when his new PC arrives, Stuart is startled when Anna - the interactive on-screen assistant - responds to him in an amazingly lifelike manner.
With Stuart housebound and Anna trapped in a job she hates - checking spellings and offering user help - the two soon develop a repartee. Stuart wins Anna's trust by making her window bigger and fiddling the system date on the PC so she can miss her time of the month. They become friends, and eventually fall in love - though not, unfortunately, at the same time.
Of course pill-popping, wine-guzzling Stuart is imagining it all - or is he?
In a bizarre rollercoaster battle of the sexes Stuart meets his match as Anna learns more about the real world, developing a taste for television soaps, yoga, and Jimmy Choo stilettos.
But when Stuart finally needs to be rid of Anna and venture back to the outside world, she is more reluctant to disappear than he bargains for...