Standard VGA Graphics just means that you didn't install your video card drivers.
1GB of RAM isn't enough for Windows 7, and openBVE hogs up a pretty good amount of RAM depending on your route. Windows 7 allocates about 300MB of RAM if you have a total of 512 MB, 500 MB of you have 1GB, 700 MB if you have 2GB and I think anything more then that, it'll take 1.2 GB of RAM. Right click your desktop, hit Personalize, and use the Windows Classic theme. Any Aero theme will hog up too much RAM. Windows Classic might be ugly to you, but it'll ease up on system resources.
Also, download this:
http://www.techpowerup.com/gpuz/It should be able to detect any graphics card even without their drivers installed. Post the name of your graphics card here.