Should I add RAM to my computer?

Jonathan has a laptop running Windows 7 and wants to double his RAM to 4GB. Leo says that's a good idea but he wouldn't go beyond that if he's running 32 bit. Online sources include Crucial.com, TigerDirect, MicroCenter, there's plenty of others. But Crucial will help him pick the right memory for his specific computer and has tools to help him install it.