There is a post on top of the FS2004 forum, on how to install into Windows 10.
If it installed in default, it will not work, also, the 9.1 update & patch is mandatory.
Why do you not want the updates?
If you have not read it yet, here goes..
1. Install into C:\ NOT into it's default C:\Program Files
2. Install the 9.1 updatel
3. Install the 9.1 nocd patch
4. Right-click the FS9.exe, select Properties
5. Select Compatibility mode, & select XP
6. At bottom, then select 'Run as Administrator'
7. Double click the desktop icon
Point 5 may be optional, if it does not work.
Welcome to our beloved 17 year old sim, that is still supported by great developers.
Nice specs on your PC, but you must remember that the sims, FS2002 & FS2004, are 32bit games and will only address 4GB of RAM, including the RAM of your graphics card. That's what normally happens when running 32bit games in a 64bit OS.
Myself, I have 8 separate & themed versions of FS2004. Golden Wings, Heritage, Alaska, Vintage, Space (?) Ford Tri-Motor, (amazing GW stuff there) & a couple of others, to keep the installs manageable, without scenery conflicts.
Anyway, have fun & there is no reason as to why you will not have the same, if not more fun with FS2004.