HP 19-2113w All-in-One Desktop Compatible ram question

[LomusMarsus]

Hi, this may be a simple question, but I am new with replacing & upgrading ram.  So I wanted to be sure in choosing what is compatible as I am upgrading my 4GB to 8GB memory. 

Can anyone help with finding the correct type of memory I would need for the HP 19-2113W All In One Desktop model? 
One concern that I had regarding numerous websites saying that this takes two 4gb cards is that the slot seems very packed already with a single memory stick, so would two even fit down into this system?  [No experience w/ this, so I'm not sure what is normal for how tight 2 sticks of ram may actually fit-- and also why a single stick of 8GB Ram itself would not be sufficient.]

Thanks for any point in the right direction

[LomusMarsus]

Also, not sure if this flails and ruins the whole situation of trying to track down the right RAM, but now, when I go to boot the computer, I am getting stuck with an endless cycle of the HP logo.

Occassionally when I remove the round lithium CR2032 battery, and also remove then re-insert the present ram, this screen will come up

and then kick back into the cycling of the HP logo starting up endlessly.   No keyboard interaction will get into boot menu or anything.    Very infuriating.. unsure if I should post this as a new topic, but this occurred after taking the image of the memory stick. If it is related to the memory at all, I'd like to know. But now this HP seems unusable.
Looked up boot-issues regarding this model computer and found a lot, but haven't seen a fix that works.  S.O.L. at this point?

[the HP logo which endlessly recurs if the power switch is pressed//where no key-interaction appears to work. oy vey.]

[Paul_Tikkanen]

Hi:

All of the information I have read seems to indicate that your PC has two memory slots, including the motherboard specs from HP...

https://support.hp.com/us-en/document/c04325034

If you look to the right of the picture that has you holding the memory chip, you will see a part of the white bracket that holds the second memory chip.

As far as why the PC isn't working, unfortunately I wouldn't be able to help you with that.

Double check to make sure you have replaced everything the way it was, is all I can recommend.

If you can get the PC to work again, this link provides compatible memory for your PC...

https://www.crucial.com/usa/en/compatible-upgrade-for/HP-Compaq/hp-19-2113w-all-in-one