Ok so I downloaded it from Atari.com and I downloaded DirectX9 and it still doesnt work, these are the popups i get:

Did you download DirectX 9.0c through the Windows Update tool or did you get it from somewhere else?

I got one form Microsoft.com, and it was the one where it downloads it once you download it... didnt work..

So I downloaded the other one where you download it all at once, then it installs... didnt work

As with many games and graphics-intensive applications, there's a whole big list of compatibility notes on their web site. Some of this may be of use to you in working out whether there's something missing or inadequate in your configuration:

V - VIDEO CARD CAPABILITY
-------------------------

RollerCoaster Tycoon(r) 3 must be played on a video card compatible DirectX 9.0 compatible. We strongly recommend you also install the latest drivers for video card. Contact your card manufacturer for the latest documentation and drivers. We strongly recommend you play this game on a computer equipped with a video card that has hardware T & L acceleration. Any ATI Radeon card qualifies, as does any 32MB Geforce 2 or higher.

VI - DISK CAPACITY AND SWAPFILE SPACE
------------------------------------

Regardless of where you install RollerCoaster Tycoon 3 you must have at least 700MB free space on the destination hard drive before installing the game. In addition, if the hard drive used by the Windows swap file is low on space, you may experience degradation in performance or random crashes; please make sure your hard drives have plenty of space for the swap file, your hard drives are free of fragmentation and that, if needed, you've used the Windows accessory, Disk Cleanup, to remove all temporary files. If Windows is installed to another drive other than C:, you must have 42MB free ON THAT DRIVE so that some temporary files may be stored there while the game is installed.



VIII - KNOWN ISSUES
------------------

WINDOWS ME AND SOME AGP VIDEO CARDS - There is a known issue with some video drivers not recognizing the AGP slot of some motherboards (especially on some of the earlier motherboards) while operating under Windows Me. In some cases, an update to drivers for both the video card AND the motherboard may resolve the issue.

WINDOWS ME AND ATI RADEON 9200 - There is a known issue with RollerCoaster Tycoon 3 running under Windows Me equipped with the Radeon 9200, where the game may unexpectedly quit and return the user to the desktop. If you've already verified you have the latest drivers and still experience this behavior, play the game in a lower resolution, such as 800 x 600. From the game's main menu, open the game options menu to the graphical settings section, and select the resolution at which the game will be displayed.

WINDOWS ME AND NVIDIA GFORCE 2 MX, GFORCE DDR AND GFORCE 2 GTX - There is a known issue with RollerCoaster Tycoon 3 running under Windows Me equipped with the an NVIDIA GeForce DDR, GeForce 2 MX or GeForce 2GTX video cards where some graphical discoloration or flashing geometry may occasionally occur. One of problems that cause this symptom is the failure of the geometry's vertex shaders to be updated properly, and this is due in part to a driver compatibility problem with Windows Me. NVIDIA is researching the problem any fixes to this will be made in a future driver update.

WINDOWS 98 AND WINDOWS MEDIA FORMAT 9 CODEC - On some computers running under Windows 98, all of the game's movies and some of the sound may not play due to an incompatibility between early editions of Windows 98 and Windows Media Format 9. Make sure you've updated Windows 98 to include all the Windows 98SE (special edition) updates.

ATI 7x00 SERIES DRIVERS (INCLUDING: All-In-Wonder Radeon, Radeon VE, 7000, 7200, 7500 and All-In-Wonder Radeon 7500) - If the date of your driver is before Sep '04, you may experience an issue regarding how DirectX uses the "specularity" and "radiosity" features of some Radeon video cards, especially the 7x00 series. If you are an owner of one these video cards, you should update your drivers to the latest version.

INTEL EXTREME VIDEO CHIPSETS - Many computers have the video chipset on the motherboard, negating the need for a video card. Some of these have the Intel Extreme video chipset. Be aware that the Extreme does not have hardware T&L and in some cases you may experience performance degradation while playing. To remedy this, start RCT3, open the game options control panel, and then select the video options page. Here you will notice several sliders that adjust the various video settings supported by the game. In some rare instances, the game's auto-configuration feature may not correctly identify your video hardware and these sliders may not be at the optimal settings for your computer. Adjust the sliders to the left to reduce the workload required by each of these settings and set the game to run in the 800 x 600 resolution setting. Also be advised that the Extreme video chipset shares your system memory to be used for video memory. You may achieve better performance by adding more system memory. For more information on configuring a computer equipped with this family of chipsets, visit the Intel website at the following address:

http://www.intel.com/support/graphics/intel915g

NOTEBOOKS AND LAPTOPS EQUIPPED WITH GEFORCE FX GO5X00 CHIPSETS (INCLUDING: 5100, 5200, 5600, 5650 and 5700) - Some users may experience unexpected graphical corruption while playing RollerCoaster Tycoon 3 at the game's highest resolutions. The symptom is evident as the game displays its "sunset" sequence, and where there are many lamps in the scene; planes of solid textures may appear to be cutting through a scene. To avoid this symptom, change the resolution of the game to run at 1024 x 768 or lower. Also adjust your display's resolution to match the resolution at which you are playing the game.

VIDEO CARD MEMORY - Some video cards share your computer's system memory. For best results, install the latest drivers for your hardware. Also consult the documentation for your video card and your computer's motherboard for optimal BIOS settings for your video card.

OLDER 32MB VIDEO CARDS WITHOUT HARDWARE T&L - Many early 32MB video cards are too old to use some of the advanced graphical features of DirectX 9 (and newer), features that are required for the 3D technology used by RCT3, such as hardware accelerated transforms and lighting (or Hardware T&L) as well as pixel shaders. If you are unsure if your video card is equipped with Hardware T&L, consult the documentation (which if hardware T&L is included will be listed as one of the technical features included in the card) or contact the manufacturer.

Thanks man, I think I found out my problem, I need to install my video/graphic card for it to work... How?

What graphics card do you have ?

Via or something

click the Start button then the Run & type in: dxdiag

look under the display tab

what is the device?

what is the driver?

Jephree your a god


Device: N/A (Ill install some disks i got to try and get some kind of display driver installed )

driver: vga.dll

Drivers will do no good if your Device is N/A

Try checking the Device Manager: RT click My Computer then click Manage then Device Manager for any "!" under Display.

Do you have a Graphics Card?

The vga.dll suggests that you are using on-board graphics.