These "Air Conflict" games (and I'd call them 'games' rather than 'sims') are not the greatest. It depends on what set-up you have, but the best WW2 combat sims (ignoring the ultra-new ones for online play and top-spec hardware) are the "IL-2 Sturmovik" series from Ubisoft, and you'd probably also like Microsoft's "Combat Flight Simulator 3".
I'm thinking back to older stuff here which is still terrific, but won't tax your system. If you can get "Battle of Britain II" to run then you're in for a real treat. Visit my Profile Page and look at my flight sim screenies...
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