How do you win at poker freerolls!
The most important strategy to adopt to have any chance of success is survival, you need to stay in the game no matter what. There are no second chances, when you lose all your chips you are out. You might have been sitting for four hours but if you get knocked out before you reach the money positions it will all have been for nothing.
Don't be tempted into bluffing too much, you will almost always find someone who's willing to call you - especially in the early stages of the tournament. Also use your all-in calls sparingly, only when you are absolutely sure you have the best hand and preferably when you have more chips than your opponent so that you don't get knocked out even if you lose the hand.
On the other hand to win a Texas Holdem freeroll tournament you need to win chips, so when you get a good hand bet it aggressively and take out the "limpers". Don't let somebody call you with a 8 3 and flop 8 8 3!
This is a slog and you need to be prepared for the long haul. Four hours is a long time to play poker online and although there is normally a break every hour it is mentally very taxing keeping up a level of concentration for that length of time.
However if you do manage to stay focused on the game, you will be at a great advantage over most freeroll players. The psychology of poker freerolls means that most people don't treat them with as much respect as they would a tournament that they had paid to enter.
Easy come easy go is often the motto.
So if you maintain full concentration throughout, adopt a strong survival-based strategy and play only good hands betting aggressively, you will do better than 90% of the entrants in a freeroll tournament.
Beating the other 10% is up to you!