Gcf extension stands for Game Cache Files. You can open gcf files with GCFScape software.
It is a temporary log file (cache) which used by Valve firms games. This file includes some informations which used during the game.
You can`t directly interfere to gcf file. However, if you use Hex editor kind of high level editing softwares, you may make some changes.
What to use gcf
which page related to gcf file
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