Default [Q] Problems with flashing my I9300

Hello guys,
my name is Raphnika and I am complete new to this.
I've tried to flash my Samsung S3 with a custom ROM like the Pacman one.(KK 4.4 or something like that).
I was not able to install it on my device so I tried the Android Revolution HD ROM and that worked for me fine.
It seems like I am not able to flash any KK ROMs to my S3. I keep getting a Status 7 Error...
I googled it and tried many solutions but none of them worked. It might be to the fact that I am a complete noob to this.

I hope you guys can help me!

lots of greetings,
Raph