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Guaranteed-fit promise
Every part is matched to your machine's slots and drive bays and checked against its published specs before we list it.
DDR3 · SO-DIMM · up to 1333 MT/s · Non-ECC · Unbuffered
2×1GB = 2GB
Spec-matched to your systemNot stocked right now. It still matches your system's specs— get an email the moment it's back.
Every option here matches this system's published specifications. Muted means it fits too — we just don't stock it right now. Pick one to switch.
SATA 2.5" SSD · SATA 2.5" Hard Drive
SATA 2.5" SSD · 256 GB
Spec-matched to your systemNot stocked right now. It still matches your system's specs— get an email the moment it's back.
Every drive here matches this system's published specifications. Pick a drive type, then a capacity. Muted means it fits too — just not stocked right now.
How we know SATA 2.5" SSD fits
Software for your upgrade — matched to your HP Pro All-in-One 3420.
Checks the drivers on your HP Pro All-in-One 3420, installs the safe updates Windows offers, guides the rest to the official download — and confirms exactly which of the upgrades above your machine has room for.
Complete your upgrade. This machine takes both memory and storage — add one from each tab above to do it in one order.
HP Pro All-in-One 3420 takes DDR3 SODIMM memory, 2 slots, up to 8 GB. Every option above matches those requirements, so it typically installs and runs without any firmware change.
“Spec match” means the module matches your system’s published specifications; it isn’t yet confirmed against a manufacturer tool.
Specifications reported for the HP Pro All-in-One 3420.
Good to know
Guaranteed fit
Matched to your machine's slots and drive bays before we list it — or your money back.
We've already matched the memory and storage upgrades that fit this exact machine to its published specifications — they're just not in stock at the moment. Leave your email and we'll tell you the moment any of them is available again. Guaranteed fit, no wrong parts.