These have been answered in other threads but I just decided to quickly throw em in one thread.

On both PCs I play these games on. These tips have worked well for me. I have used them in the past with my CD copies too.

Go in the games folders and find the .exe files. First in RollerCoaster Tycoon Deluxe. Right click on RCT.EXE & goto Properties.

Then click on the compatibility tab. Click Run this program in compatibility mode & select Windows 98 / Windows ME. Then check mark Disable visual themes.

Then click Apply & OK.

Now go in the RollerCoaster Tycoon 2 Triple Thrill Pack folder and right click on RCT2.exe and goto properties.

Click the Compatibility tab and just check Disable visual themes. Then click Apply and OK.

Both should run fine.

Now just select a resolution you think looks good scaled to play RCT1 in widescreen or maybe play both in 640x480 scaled to widescreen if you want a more zoomed in game.

Go in your Video card settings and enable GPU scaling and select full screen.

Hope this helps. ;)