masses of weeds ?

What is the best and longest end result solution to clearing weeds in block paving drive and slowing/preventing re-growth.
Many thanks in advance

Tip: for those who have to pull out a large area of either block, or modular paving. Immediately shutter around the remaining blocks to prevent movement. This was told to me by a mason working for a contractor when I pulled up 30 modular paving slabs for GPO telephones. If you don't he said you wont get the last few back in as the remaining ones would have moved in to the gap slightly enough to cause a replacement problem where you will have to cut the last remaining to get them back in.