Thinking of Upgrading Motherboard for a Dell XPS 8100

I currently have a 2-year old Dell XPS 8100, with an Intel i7 860 CPU at 2.80 GHz, 8GB RAM, 500 GB Hard Drive, 64-bit Operating System, and running on Windows 7 Home Premium. The motherboard is a T568R. This desktop has chewed through two Hard Drives and on its third, which is starting to sound like it's on its last leg. I've experienced random computer freezes, blue screens of death, and once my fans started clocking in like crazy, running on turbo speed and the entire desktop and computer screen blacking out. I couldn't Crtl + Alt + Delete or power off. Only by flipping the power cord switch was I able to shut it all down. These problems are completely random and happen at any time during any task and have been happening after replacing the two hard drives that crashed.

I don't do anything heavy, in my opinion. I play games such as Sims 3, Final Fantasy 11, and other random PC games, but no heavy streaming, downloading, uploading, or moving files. I was told that my motherboard could be faulty and to look into replacing it. Because my computer is somewhat outdated and no longer under warranty, should I just save and buy a new computer? Or should I replace the motherboard with the same model or is there another motherboard that is compatible with a Dell Studio XPS 8100 and somewhat easy to install? I've never touched the inside of a computer, so should I go to an expert to replace the motherboard should I go that route? 

Thanks in advance for your time and opinions!

Seraphyn