Give it a try...
FS 2004 is user-friendly regarding Hardware...
An upgrade to the Graphics card will improve matters somewhat, but you should be good to go..
...!
Just have a fiddle with the various sliders....
...and....lock your Frame Rates to 20-25 FPS MAX!...for "Smoothness"...
...!
Have fun!
Paul...G-BPLF....FS 2004... 8-)...!
I doubt that you would be able to run "FSX" on it without considerable problems!
Win 8.1 64-bit. DX11. Advent Tower. Intel i7-3770 3.9 GHz 8-core. 8 GB System RAM. AMD Radeon HD 7700 1GB RAM. DVD ROM. 2 Terra Byte SATA Hard Drive. Philips 17" LCD Monitor. Saitek Cyborg X Fly-5 Joystick. ...and a Briggs and Stratton Petrol Lawn Mower.