Black screen after windows splash

At the start of December I did a factory reset on my M15x. Never had a problem with it before then, but at the start of December over night everything seemed to fall apart. Chrome was my browser at the time and upon opening Chrome all of the addons would one by one crash and then the browser itself would go to it's error screen. I assume it was just a Chrome problem but then Itunes forgot the path of all of it's content and a few other programmes were giving me a hard time. Upon attempting to uninstall google chrome, the screen would go black half way through the uninstall process and I'd just having my mouse cursor (still moveable) and flashing. I think the content was still running in the background, but the screen was just acting up. Sorry if I'm a bit hazey on the details of the problems here, it was last month and I thought I'd fixed all the problems. So I was getting black screens with uninstalls and blue screens if I tried to actually use Chrome. I read there were some problems with chrome's addons and a flash player update, but not of the solutions helped and I can't understand why I would also be getting the other issues.

Did a factory reset. Downloaded chrome again onto a clean windows 7. Same thing happened with the crashing browser and crashing addons. Managed to uninstall it, switched to Firefox and thought I'd solved any problems that I'd been having.

Thought nothing else of it until this morning. This morning I had the whole thing lock up. I was just browsing with Firefox, I just flicked stealth mode on and off because it looked like it's light was on and I wanted to check. Whole thing froze up so I had to do a force restart, this is where it gets fun. Upon getting past the windows 7 splash screen, everything goes black. It's not a dead black, the screen is still lit up, but it's black. Everytime I have to force a restart and everytime it'll get to the same spot and go black. It runs fine in safe mode so I tried to reset it back to last week. The process of returning it back to a previous state took forever and eventually threw out an error BUT afterwards it did actually get to the desktop and I assumed we were all good again. Wrong. After a reboot I was back to square one.

This is where it gets really really fun: I decided to cut my losses and do another factory reset. The reset function ran fine and once again I assumed I was out of the woods. After the reset it reboots and should start up like it did out of the box.... I get to the splash screen and then I get black. Even after a factory reset. I know the reset worked because I can run it in safe mode and get to the part where you put in all your new user details.

It's a bank holiday so I can't get a hold of Dell, so I'll call tomorrow, but if anyone has any ideas that can help me out or help me explain it when I call up, would be much appreciated.