Julia,

If you want to access the files you don't want to lose and save them to a thumb drive, put the old hard drive back in the old computer. On your new Dell, burn an image of free Ubuntu flavor of Linux on a CD. Insert the CD and boot off it. You might have to change the booy sequence. "Try Ubuntu Without Installing". It's easy to do and will save your files. Here's the article: https://www.pcworld.com/article/2147063/linux-to-the-rescue-how-ubuntu-can-help-a-computer-in-distress.html

Tom