Video Drivers/FrameRates
Looks like you are using a relatively slow RAM for a start.
PC133 is a tad bit slow because it running at a bus speed of 133Mhz. The newer DDR RAM are much faster and some clocks in excess of 333Mhz depending upon the type of motherboard you have.
With regards to your video card, the Elsa GE Force 2MX should be fine but you may have to overclock it a bit. In fact Elsa makes great video cards and there is little noticible difference between the Elsa GE Force 2 to another branded GE Force 3 card. I have changed mine and there was no real difference except a hole in my pocket!
In fact you may also try to overclock your CPU and run your OS clean of unnecessary TSRs to max your machine out. Every bit of TSRs running in the background such as antivirus, ICQ, etc robs the performance of your CPU.
You may also browse to Toms hardware page on the net to learn about overclocking your PC. This helps you get the max out of your PC in more ways than one.
One way to max your CPU for G2 is to use a multi-boot application to allow multiple copies of OSs to be installed on one machine. Acronis OS Selector is an example of pretty good multi-boot software where you can load multiple copies of your OS and select one just dedicated for G2 assuming that you have enough harddisk space and keep it clean of any unnecessary programs except perhaps internet connection for updates.
By the way Windows 98SE is a great platform for games so keep it for as long as you can. By the way G2 also works on Windows 2000 and XP too.
So far I have used the following PC configurations quite successfully to run G2 silky smooth. This PC is purpose built for flight sims.
Intel P4 2.4Mhz
Apacer 512Mb PC2700 DDR RAM
Maxtor 80Gb , 7500 RPM, IDE ATA 33 HDD
Asus GE Force 3 Deluxe Video card
Creative Labs Sound blaster live value
Chaintech 333Mhz motherboard.
Windows XP
This machine is a tad dated by today's standard but seems to run pertty much ok for all of my present flight sim programs. In fact the most demanding flight sim that I have is the Microsoft Flight Simulator 2000 and 2002. Boy this sim sucks CPU juice and usually dictates my PC upgrade path.
Hope this helps. Just email me if you have any problems with PC hardware.