While in the game save your game in any available slot.

Then exit out of the game and go to: Documents\Rockstar Games\GTA IV

If you dont see folder named (savegames) follow tutorial

If you see folder named (savegames) then just drag SGTA4xx file from download link and ur finished.

Go to start menu and type in %appdata%

Then click on the very top where it says "AppData"

Then go to: Local\Rockstar Games\GTA IV\savegames\user_**********

You should see 3 files in that folder (ControlMap.dat and SGTA4** + SGTA412 )

Delete both files named SGTA4** and SGTA412.

Download GTA IV savegame from here.

Drag out savegame from winrar to folder: Local\Rockstar Games\GTA IV\savegames\user_**********

Rename xx to any nubmer from 00-12 (nubmer are save slots in game)

Then copy that file and rename it to SGTA412

Now you can start the game.

If this shows up to you that means you need to use xlive file to be able to use savegame.

Why so? Because you may be using Games for Windows Live as I do.

Press enter, wait it to load and then exit the game.

Go to your GTA IV game folder where you have installed it and drag xlive.dll and xlive_d.dll files from winrar you downloaded earlier.

What does xlive.dll and xlive_d.dll do? It stops you from playing GTA IV multiplayer so you could play single player free and using savegames.

Of course you can delete them later if you would like to play multiplayer again.

Now go to: Documents\Rockstar Games\GTA IV

Now you should see folder named (savegames) if you still dont see it, create one.

Go to the folder savegames.

Copy all files from folder: Local\Rockstar Games\GTA IV\savegames\user_*********

to Documents\Rockstar Games\GTA IV\savegames

And now you can start the game.

Now you should have 100% completed GTA IV

Enjoy playing!