HP RF243AA-ABA M7640n
Desktop, from 2006 2 hardware reports
Memory

Up to 4 GB
4 full-size slots
Drives and power
Coming next
Checked from separate sources
Only 2 machines reported so far, so this answer rests on few examples. Check the label or open the panel before you buy.
Upgradable
Yes. 4 slots, up to 4 GB seen working.
It takes DDR2-533 full-size sticks (DIMM).
- Slots
- 4 DIMM slots
- Type
- DDR2-533 240-pin DIMM
- Most seen working
- 4 GB in two or more machines
- Firmware says
- 4 GB maximum
- How sure
- 2 of 2 reports show this layout
See 8 GB DDR2-533 DIMM on AmazonOpens an Amazon search for this exact spec.
Worked out from 2 hardware reports of this desktop. Sources and method. Updated 9 Nov 2026.

4 full-size slots
Illustration Questions
Can I upgrade the RAM in the HP RF243AA-ABA M7640n?
Yes. 4 slots, up to 4 GB seen working. It takes DDR2-533 full-size sticks (DIMM).
What type of RAM does the HP RF243AA-ABA M7640n use?
DDR2-533 full-size sticks (DIMM, 240-pin).
How much RAM can the HP RF243AA-ABA M7640n take?
Machines in the reports run up to 4 GB. That matches the 4 GB maximum the firmware reports.
Is this my desktop?
Check the model name on the front or the label of the case. It should read RF243AA-ABA M7640n.