......and want to build a dream system that can run FS9 and FSX with great smoothness,without a slide show.and good resolution I have Level D and PMDG panels currently.Also I have CH yoke and pedals. So with that in mind what kind of system would you build....Would you use Vista or XP.

O/C the Q to 3.6Ghz and Surprisingly, this is Still within 10% of the best that is available - at any price -. http://secure.newegg.com/NewVersion/wishli...tNumber=7162186That last 10% will cost you another $1000. Keep in mind too, Nothing available today, or until a (fully) multi-core capable FS (11?), combined with an 8 core CPU (Nehalem v2?) will - ever - be able to run FS at 100% and the PMDG 744. That's why I generally argue that last $1000, 10% is really quite useless.

Good advice from Sam,However, I'd stick with XP for now, or ideally get another hard-drive and dual-boot with Vista64 and go for 4GB RAM instead of 2GB.RegardsJim

Would you re-use your existing monitor? If so, then I spent less than $2000 for mine, specs below. And it rules FSX with the CLS DC-10 (I know, that's not as fps-intensive as PDMG, but it's the closest comparison I can make).RhettE8500, Arctic Cooling Freezer 7 Pro, ASUS P5E3 Premium, BFG 8800GTX 756 (nVidia 169 WHQL), 4gb DDR3 1600 Patriot Cas7 7-7-7-20 (2T), PC Power 750, WD 150gb 10000rpm Raptor, Seagate 500gb, Silverstone TJ09 case, Vista Ultimate 64