The challenge is that you're using an external drive and, whenever your computer boots up or you plug in the drive, Windows sees it as a new drive and it breaks all the connections in Premiere Elements.
If you leave the drive plugged into your computer and permanently assign it a drive letter (using Map Network Drive), Windows will realize it is the same drive and Premiere Elements will not lose the links.
BTW, have you ensured that your external drive is formatted NTFS rather than FAT32 (as they come from the factory)? FAT32 drives have a file size limitation that can stifle video editing.
Thanks for the suggestions.
Unfortunately, I may not have followed your steps correctly. When I did a Map Network Drive on my external hard drive and tried to open my project, I get a scratch disc error. I googled the instructions to do a Map Network Drive and "think" I understood it that an external hard drive needs to be a shared, networked folder? The "network" part may have caused the scratch disc error.
Am I better off NOT using an external HDD? If so, is it just a matter of copying and pasting (or moving) everything that is in my external hard drive to a designated folder within my internal hard drive? I am quite concerned about the space I have in my internal hard drive, 500GB as I feel I will run out of space with all the raw footage and music I want to use or plan on using. (By the way, my external HDD was NTFS.)
Your input is greatly appreciated.
Using a networked drive, mapped, or not, is likely to yield errors.
For your external HDD, you can go into the Disk Management in the OS, and set the drive letter, so that it will always be constant, regardless of what else is, or is not plugged in. I do this constantly, as I migrate my Projects between my laptop and my workstation - each has a unique drive letter, and it is the same for the OS for each computer
For material that is on my NAS, I just Copy the Assets over to either a local, internal HDD, or to my external, with the set drive letters.
I would keep networked drives out of the mix, or you will have constant fights on your hand.