The Basic Rules... First of all make sure you have played at least once and saved your game in the process. And must have completely closed/ exit the game.

1. Go to "Start", tupe "Regedit" in search. Launch it once it is found.
2. Once you got the Regedit running look for "Telltale Games" key.
3. Which contains several Keys "JPScore1" etc. (Will have more keys related to Jurassic Park and some of other Telltale Games, we'll talk about the rest later)
4. Now click on "JPScore1" and you will see some information as displayed on the image. Saying "1", "REG_SZ", "0" Every Number stands for one Episode. The scenarios then are each numbered and given a value ("-1", "0", "6"...). If you change the value from the scenario which is locked from "-1" to a positive Number - eg "0" it should help you to acces this scenario. SO, "1" stands for Episode's Scenario number. "0" means the scenario is unlocked but yet to complete. Adding A New Episode: But above way only lets you to replay the scenarios which will not unlock the story nor "Load" game option. And will NOT unlock any episodes or scenarios by playing them.
5. So now here's the question "How to get to second Episode"? Well, lets get on working on it as well. Click on "Telltale Games" key -> "New" -> Key
6. Rename it to "JPScore2".
7. Now in it, "Right Click" -> "New" -> "String Value"
8. Once the String Value is created, right click on it and click "Modify"
9. Put "0" on "Value Data" AS PREVIOUSLY STATED, GAME MUST BE LAUNCHED TO SAVE REG DATA. NEWSFLASH FOR GENIUS - You can unlock any episode by creating new keys as JPScore1, JPScore2, JPScore3 and JPScore4. As long as you done accordingly as above instructions. I hope you got it. If not no worries we can go deeper. Conclusion & Finishing Off Loose Ends: Remember I told you we will talk about some keys earlier, and guess what now is the time.
10. Get yourself to "JPScenario" key. And make sure to make your key values ar same as the image shown here. It will have different values than showed in here. Make these values to your game.