Memory upgrade
I have an Hp 400n desk top 256mb I need more memory what do you suggest?
A newer computer, if you have 256mg that indicates to me you have a very old computer. No computer has come with 256mb of ram since the early 2000's.
Even if you upgrade the memory and spend $60+ the computer will still be slow due to its age. You are better off investing a little more and even with the low end computer of $250 you are still way better off then adding memory to your old computer.
The different in performance will be by a very large margin