rfactor.net to download and buy the game.
There are 2 types of 'mods', there are Tracks and Mods. A track is just a track, a Mod is cars and in some cases a track too.
If they are an exe its pretty simple, just run the installer, I have never used win7 xp
but if it's anything like win7, just make sure the mod installer points to program files (X86) not Program files.
Some mods are in a rar or zip or 7z, if that's the case you need winrar from rarlabs.com, then you open the archive and check for a readme, it will usually have install instructions.
If no instructions exist, open the rar and look at the folders, if you see folder's 'GameData' 'rFm' etc, just open explorer and navigate to your rFactor install folder, then drag and drop the files in there.
If you don't see GameData (usually for tracks) and you see a folder with the track name, navigate to rFactor\GameData\Locations and drag and drop the folder in there.
Sometimes tracks are packed incorrect and are in a folder in a folder, if they don't work after install, open the locations folder and check the track to see if this is the case.
99% of all mods are packed right.
I hope this helps and doesn't confuse you, It can be confusing at first, but after the first time it gets easy
