edit : solution for this problem was mentioned on the first page . i look to bios but i couldnt find anything useful pls help me i dont wanna format my mint
i am using gt 540m with optimus technology. i installed bumblee project a month ago but just before installing nvidia driver today , i've deleted it from package manager. recovering my system is more important for me now than install nvidia driver
solved by myself
If you are installing the Nouveau drivers after uninstalling the Nvidia ones, be sure to delete the /etc/X11/xorg.conf file that the Nvidia driver created (or undo the changes), or else X will fail to properly load the Nouveau driver.
Install the DDX driver with the xf86-video-nouveau package.
Also make sure you have Xorg properly installed.
If you want hardware-accelerated 3D support (to run GNOME Shell or KWin's effects, for instance), install the DRI driver with the nouveau-dri package. For Arch x86_64, install lib32-nouveau-dri from the Multilib repository, as well.
this worked for me finally i get my full screen back ! and i decide to use primus for bumblebee