So I have (maybe had) a FB322LL/A - Refurbished iMac 24-inch 2.8GHz Intel Core 2 Extreme early 2008 model. The last 2 months I have been having random crashes, the nice "You need to restart your computer. Hold down the power button for several seconds"message. I removed some apps and removed some old items to free up hard drive space, which seemed to help. Today I was running powerpoint with mozilla and got an ugly looking screen all these red squiggly lines (image attached). I was able to restart once and get back the desktop but this occurred again shortly after the restart (image attached). Now I get can't get past the apple logo and it doesn't even look like an apple logo anymore. So I don't know where the issues is coming from. I am wondering about the GPU or is this a virus. Please help!!!