National Lottery operator Camelot expected to sell 200 tickets every second – or 720,000 – during the hour before the draw closed at 7.30pm.
But many were greeted by a message saying that the website was “temporarily unavailable” because it was “extremely busy”.
The UK’s biggest ever Lotto jackpot sent ticket sales soaring ahead of the draw last night along with the threat that if the full amount was not won it would be shared out among winners of the Saturday night draw.
The inflated jackpot is the result of 13 consecutive rollovers. If nobody picks the six correct numbers tonight, a larger kitty will become available on Saturday. If it is still not won, it rolls over one more time to the next draw.
Dedicated Lotto fans will curse themselves over the week they forgot to put a quid on their favourite numbers, however.
The statistics show that the RM postcode, which includes Romford, Dagenham, Hornchurch, Grays and Purfleet, comes out top.
Under Lotto rules, when the jackpot reaches £50 million, someone with five correct numbers can win, lowering the odds considerably.
The biggest cheque won on a single Lotto ticket was £22.5 million shared by work colleagues Mark Gardiner and Paul Maddison from Hastings in 1995.
However if no-one wins the jackpot this week, Camelot will enact new regulations which stipulate that it must be shared out.
In addition to the jackpot, National Lottery Camelot will make one person a millionaire with its Millionaire Raffle, which has created 67 millionaires since October a year ago.
A National Lottery spokeswoman said Wednesday’s jackpot had the potential to make one of its biggest winners in the lottery’s history.
Dr Simon Goodwin, a senior lecturer at the University of Birmingham’s School of Mathematics, told Sky News: “Players have less than one-third of the chance of winning the jackpot than previously”.