Dell XPS 15 windows 7 reinstall problems. Please help!

Hi,
My Dell XPS 15 L521X has recently had some problems. It began when I tried to reinstall Windows 7 using an .iso image on a USB drive. This came with a problem as when I got to the selecting drive screen in the installation, there were no drives to be seen. I somehow managed to do a system restore back to when windows was first installed on my computer, almost 2 years ago now. I wasn't satisfied with this and continued to try to reinstall the OS.

The main problem is that there are no drives ween during the OS installation and I also want to wipe my disks clean. I have backed up everything so anything left on my PC can go if need be. I have tried updating the drivers by downloading and installing from the dell website but some of them refused to install, requiring a much more complicated process or just not starting at all.

I have been looking at multiple places around the internet to try to find a solution to my problem and have tried doing a few, but this seems to have possibly made things worse as now my start up repair option from the bios now leads to a "blue" screen which says "a problem has been detected and windows has been shut down to prevent damage to your computer. of this is the first time you've seen this stop error screen....." and so on. I don't know if you have ever encountered this error before but I have now seen that multiple times. 

I heard that sometimes it is a USB port issue. I have checked and I believe all 3 of my ports are USB 3.0. I know this by looking at the symbols next to each port. They all have this symbol next to the ports.  

Can anyone help with this? Thanks a lot