Hi guys, I had a couple of problems with my iMac lately: Flash (Firefox) seems to crash several times an hour after trying to view non-specific Youtube videos. The browser itself (Firefox) has also crashed a number of times, although that's much less common compared to the crash rate of Flash. To an lesser extent, other programs have also crashed (e.g Audirvana), including two random Kernel Panic's since I've bought this computer. I'm suspecting that a RAM stick is defective, as they're not Apple's original memory sticks. Do you guys know how I can test the RAM sticks to find out which one's faulty? I've read about Mac's having a built-in RAM test, unfortunately, I haven't been able to start it. I've been recommended to use this program. Since this is my first Mac, I'm extremely paranoid about viruses/malwares. Is this safe, and will this work on Yosemite (the link's from 2011)?