The odds of getting the jackpot with a Euromillions ticket are roughly 1 in 76 million. (For comparison, the odds of getting all 6 numbers with a Lotto ticket are roughly 1 in 14 million).
Your suggestion of buying up every possible combination has three problems:
1. You'd never be able to do it in time. To count to just 1 million (counting 1, 2 , 3, 4, 5 .. with one number per second and not stopping to sleep, would take about ten and a half days). So to complete 76 million lottery tickets (even if you could fill out one per second, taking care not to duplicate any entries or to miss any combinations out, at one per second) would take over 2 years.
2. Since Euromillions tickets cost �1.50 (rather than the �1 for a Lotto ticket), you'd end up spending more than the jackpot payout.
and
3. If several people shared the jackpot, you'd be even further out of pocket.
Chris