How do i get my files to open properly?

[Timvh1 0]

I've been trying to open and install buildings and modds I have downloaded onto my game, but most of them say they don't know what program to use and can't do so without. I have tried and tried but they won't open properly. The only exceptions are files that already have an installer built in, like kevdan25's McDonalds v2.

Can someone please help me by giving me some feedback and ideas?

Timvh1

[CaptCity 4,669]

Sounds like you're trying to open .dat files. This is not necessary. Downloads usually come in Zip folders. These can be unzipped or the contents dragged out of them and into the game's Plugins folder found in the C:\Documents and Settings\*User Name*\My Documents\SimCity 4 folder. The only type of file that needs to be opened/run are the .exe files. Others such as .dat, .SC4Model, .SC4Lot, and .SC4Desc, are used directly by the game as is and should just be placed into the Plugins, preferably in some type of arrangement that makes them easy to find.