Hi Aziz
Your Windows seven is it 32-bit or 64-bit version?
For the 64-bit, if you are sure you installed AMD
drivers and its CCC then you should be able to find it in this folder
C:\Program Files (x86)\ATI Technologies\ATI.ACE\Core-Static
You can see the catalyst control center program (CCC.exe) and it mostly reside on the taskbar icon notification (right corner)
About game screen,
Most of the game screen size is determined by the game, there is always an option (menu) for full screen or windowed. If not, then it might probably a windowed game.
Make sure that you have the correct screen resolution which is at 1280x800 for most Toshiba A305.