What is your system? (XP, Vista, Win 7, Win 10, Linux, MAC etc)
Is it a PC or laptop?
If laptop, does it have more than one graphics card?
What is the make and model of your graphics card?
Are you using the 32 or 64 bit version of C2?
Have you tried a total clean install? i.e. uninstall c2, delete or move the remaining folder (in case there are non-standard plugins you want to keep), reboot, download latest beta and install. Run C2 and check.
Have you installed anything recently that may have altered your PC settings?
If your vision so exceeds your ability, then look to something closer.