weird(and aggravating) computer issue

Occasionally, I'll be playing a game(TEW 2007 if it matters) and after I hit "next" to go to the next day, it will load and then the whole window is black except where the text box would be. That's all white. If I close that and try to reopen it does the same thing.
First I figured it was an issue with the game. Then I tried opening Firefox to go to the game's website to find some answers. When Firefox opens its nothing but a grey screen. No matter how many times I close and reopen Firefox it still wont load. So far my only solution is restarting my computer, and that's just to annoying to have to do every single time.
It all started when I had to install Cisco Clean Access Agent and McAfee antivirus. I have to have them on my computer in order to be connected to the internet in my dorm room.
I am getting extremely aggravated. Anyone have any idea how to fix it?
First I figured it was an issue with the game. Then I tried opening Firefox to go to the game's website to find some answers. When Firefox opens its nothing but a grey screen. No matter how many times I close and reopen Firefox it still wont load. So far my only solution is restarting my computer, and that's just to annoying to have to do every single time.
It all started when I had to install Cisco Clean Access Agent and McAfee antivirus. I have to have them on my computer in order to be connected to the internet in my dorm room.
I am getting extremely aggravated. Anyone have any idea how to fix it?