Could not initialize Photoshop Elements

It means, typically the hard disk they are installed on is basically full.    A reasonable rule of thumb: Keep at least 10% of your capactiy free- it 's used for temp files. 

It can also mean that whatever disk you are using for your adobe temp directory is full- often just choosing another partion is enough. 

If on windows:  I first search for *.tmp files on my c: drive.   The asteric means "find all the the files that end with tmp."  Find them, and delete them. 

It sound's like it's time to get a bigger hard drive:  SSD is the way to go.   A new hard drive in your case needs to be bigger than the old one- usually this means going from 1 TB to 2TB, or larger.

I purchased some software that lets me transfer stuff to a new hard drive- you simply cannot drag and drop program folders.

A big space hog for me was all my picutres:  JPG, PNG, and PSD's-- something around 125GB- so I moved them to an external hard drive.

I also purchased an expansion card, which lets me add new hard drives.   One with 4 ports in it- I can plug in two more hard drives.   Curently I have 4 Hard drives- 3 are SSD's (solid state drives- no moving parts) and one is a regular HHD- plus I have one external 3  TB HHD.   I've got copies of copies of backups.   If I start to run out of space (One program alone MS flightsim 2020 currently hogs up 345GB of space) I will just buy another SSD, plug it in and Im good. 

IF YOU HAVE A LAPTOP:  You can clone a small hdd to a larger hdd-- SSD is the way to go.   Use an adaptor to clone the old hard drive to to new one (connected thru a USB port), then swap out the old hard drive in the laptop with the newly cloned hard drive.   It might take a while to do- the last time I cloned a 2 TB SSDd to another SSD using a usb port- I just started the cloning process, and went to bed. 

I also have 3 ssd's and 3 HHD's just sitting in a desk drawer- I play with those.