I have tried lots of Lotto programs and I'd have to say Expert Lotto www.expertlotto.com
is by far the best and most powerful, although quite complicated and most suited to advanced users.
It does however, feature a users forum that offers new users heaps of good hints & tips on using the software.
Lottonet XP is total and utter crap.
Lotto Pro 2007 is not a good performer, although very user friendly and the best looking & laid out. Just that it has never given me a win in 2 years of regular use.
If you are the mathematical, statistical, analytical, 'nerdy' type, grab Expert Lotto Pro.