The error code (2000-0146) means there's a issue with the hard drive and most likely needs to be replace with a new one. However, since you're able to boot into windows, I suggest you run Chkdsk / r into the command prompt(Admin) and see if that will resolve the hard drive problem.
Secondly, I suggest you quickly backup all your photos, documents, flies, music and other important stuff to either a flash drive, external drive or some type of backup software such as Acronis. You can even use the free windows tool to backup all your important stuff. Please click link below.
Or run Custom Test on the hard drive in the Dell Product Support page. In link below, please click on diagnostic, 'Choose a diagnostic test' and then hard drive.