This is a bit of a puzzle... The specs for Inspiron 3880 say it has one PCI-e x1 expansion slot available on the motherboard (not counting the PCI-e x16 slot used for a video card). BUT...the motherboard picture doesn't mark that slot. I presume it's the gray slot to left of the blue PCI-e x16 slot (#10) used for a video card. So assuming that is the PCI-e x1 slot, that's you're only option. In theory, the PCI-e x1 slot should be compatible with a PCI-e x1 USB 3.2 card.  You do want a card that only needs power from the slot and doesn't also require a direct connection to the PC's power supply. Which size PSU do you have, 200W or 260W? PSU size might be a limiting factor, especially if you're going to use a lot of power hungry USB devices (printers, scanners, etc) at same time. Would it be easier to get a USB 3.2 hub with its own external power supply? Connect the hub to one of the four USB 3.2 (Gen 1) ports on this PC and plug its power adapter into the wall. Then plug some of your extra devices into the hub.  A 4-port USB hub would net you an increase of 3 USB ports, since the hub will use one of the four ports on this PC.
Hi there! I need to add a USB root hub / more 3.0 ports to my Inspiron 3880, and was recommended a PCIe USB card.  How could I find out if there is any PCI that would be supported by this Dell model? And what would be the best way to understand the compatibility between the Desktop and a PCIe USB card that I could buy off Amazon e.g.?  Is power supply something I should be concerned about here? As it is probably obvious by my noob questions, I don't understand much about this subject, but before considering taking the Desktop to a professional, I would like to at least understand if adding a PCIe USB card to the Inspiron 3880 is even possible. Thank you so much!  
Installing a new PCIe USB card in my Inspiron 3880