You can pirate it.
I had that game for a long time and I decided play it again, but I couldn't.
I installed the game and later it asks me for a serial key. I open my gta case and the booklet is not there(I know i had it).
Since I lost it, is there a way I can play it?
Just Google GTA 4 Serials and you should get some Valid Serials to use...
If you have the original DVD you don't need a crack. In that case you should find a working keygen. You will have access to the same features as in the legal registered version ;-)
~Donater since 19th October 2011~
~Ex-Crossfire Minion || Resigned on 4th February 2012 ~Da fuck
u can play it but u need to find the thing
find a crack for the game, but by cracking it i dont think you'll be able to play mp
Do not go gentle into that good night,
Old age should burn and rave at close of day;
Rage, rage against the dying of the light.
~Donater since 19th October 2011~
~Ex-Crossfire Minion || Resigned on 4th February 2012 ~Da fuck
Just go buy it again. best way