Frame rate win_98 vs win_xp

Please tell me why...
I have a dual system computer with win_98 & win_xp
Of course I have the same hardware . I have both fs9 and flight sim 2002 installed.
I can activate each flight sim from each operating sys.
For unknown reason at the same setup at Meigs field the frame rate with win_98 is about 20% higher then with win_xp. (31-32 in win_98, 24-25 with win_xp, fs 2002)
Is there any reason for that ?
My hardware is AMD Duron prosesor 801 MHz 384 mb RAM with NVIDIA mx440 video card. The flight sim setup is minimized.

One reason is because there is a lot less going on in the background in 98 than XP (even if you shut everything down)

You can make win98 super fast by useing a couple of progs -HyperOS and 98Lite (costs over £100) but you can run your computer on 1gig Ram with the system running from that Ram and not the hard drive ( now thats fast)

I will see if i can find the link and post later

Found it

Its under 98 lite parts 1 & 2

http://www.micromart.co.uk/content/features/default.asp?category=search&type=2&searchtext=long+live+98&Page=2

I know we are a little off course here but it just makes you wonder