Used and was working when removed from computer. Sold as-is. I will not be responsible for people who can not install these properly, and set them correctly in BIOS.
your dell xps 400 take ddr2 PC5300. These would not work with the current ram it uses without conflicts. (they would cause your current ram to run at lower than recommended speeds).
np. in the future ill have some more ram in your speed range if you dont find some till then. just remember you can only have 4gb of ram in that system at 1 time.