The following are the minimum requirements for running FSX-Steam. So comparing with your information, it looks like it will run but you will certainly not get good performance from the Sim. As well, you will not be able to add on any payware aircraft/scenery as that will require a better graphics card and more processing power. You may need to first put all your settings to the lowest and then slowly increase them until performance drops.
If you're wanting to upgrade your computer in the future, your minimum processor clock speed should be 3.4 Ghz and over (maybe with a slight overclock to 3.8 Ghz) and a later version of Nvidia card. You've bought a good Sim - just try loading it and see if there's any problems. Shutting off UAC and Anti-virus temporarily will help with installation from your media.
SYSTEM REQUIREMENTS
MINIMUM:
- OS: Windows® XP Service Pack 2 or later
- Processor: 2.0 Ghz or higher (single core)
- Memory: 2 GB RAM
- Graphics: DirectX®9 compliant video card or greater, 256 MB video RAM or higher, Shader Model 1.1 or higher (Laptop versions
of these chipsets may work but are not supported. Updates to your video and sound card drivers may be required)
- DirectX: Version 9.0c
- Network: Broadband Internet connection
- Storage: 30 GB available space
- Additional Notes: Broadband internet connection required for multiplayer features
© 2015 Microsoft Corporation. All rights reserved. Microsoft and Windows are trademarks of the Microsoft group of companies. (c) 2015 Dovetail Games, a trading name of RailSimulator.com Limited (“DTG”). All rights reserved. Dovetail Games is a registered trademark of Dovetail Games Limited. All other trademarks are the property of their respective owners. Unauthorised copying, adaptation, rental, re-sale, arcade use, charging for use, broadcast, cable transmission, public performance, distribution or extraction of the product or any trademark or copyright work that forms part of this product is prohibited.