Where are you flying from, to Geneva?
 
Odds are you have to go through customs and immigration after landing (unless this is a flight just within Switzerland or some other odd exception), and you will definitely have to check in again for EasyJet. You cannot interline your luggage to EasyJet and you will have to collect it.
 
Note that the 40-minute restriction means you have to be checked in 40 minutes ahead of time. If you are still in the lineup, and the 40-minute deadline occurs, you won’t get on the plane.
 
I think the odds are very good, if your first flight is not delayed. Just keep moving quickly and don’t pause until you have gotten checked in to EasyJet and through security.  

Thank you for yr info.
 
I’m flying from Singapore to Geneva by KLM.
 
Best Rgds,
Siew

So are you stopping in Amsterdam first?

Yeah, I’m with Traveler on this—Easyjet and other ‘low-cost’ airlines are almost always ‘point-to-point’ only, meaning no baggage check-throughs. Plan for that, and when you check in at SIN, ask if it can be checked through to PRG, but don’t expect it. (BTW, What will you do if KLM misplaces your baggage?! Be sure to include the address at your actual destination both on a tag attached to the outside of each piece, as well as placing it inside a zipped pocked that can be easily accessed).

Yes! I am stopping at Amsterdam(Schiphol).By The way, this is the first time I’m taking KLM, did the KLM flight always on schedule or it is prone to delay?
 
Rgds,
Siew

Check here for statistics on your routes:
 
http://www.flightstats.com/
Click on
Historical Ontime Flight Rating
 [/align]Don, what are the rules about having to reclaim your luggage and recheck it for the next flight? Does that only happen when you are entering the US from abroad and have to make a connection, or do other countries have a similar requirement? Would Siew have to go through customs and immigration in Amsterdam?[/align]

Unless it can be checked through, Choyh’s gonna hafta schlepp baggage at Schiphol. Generally, you clear Customs (with baggage) at your final destination within Schengen-zone, but sometimes must go through passport control enroute (without baggage). Each Schengen member country can adjust and reinstate stricter controls on it’s own border/entry requirements as it deems necessary. Switzerland is not part of Schengen border agreement.