Will PC2-5300s-555-12-e3 DDR2 memory interchange with pc2-5300u-555-12-e3?

I don't think they will. One may be for laptops and the other for desktops. You will have to check the pins, since the 240-pin package is for desktops and the 200-pin package is for laptops.

When you choose memory, you need to make sure that it is the correct type (plain SDRAM, DDR, DDR 2, DDR 3), the correct number of pins (since laptop and desktop memory are different), and a compatible speed (you can usually use faster than required, though you might have to mess in CMOS). Most of the time, you'd use unbuffered, non-ECC memory.