both are 240pin ddr2 ram and would physically plug in 530.  the second one 5300unbuffered would work. not sure what speed of the 1st one is. my 530 for unknown reason would not install Win 10.  Win 7 install is smooth.  maybe it is using an older mobo from Dell (Dell makes two different mobo one of which does not support quad core 2).  
Many thanks for any help. This is a backup computer I am working on.   The RAM that I have in hand is: 1GB 240-PIN DIMM 128Mx641 DDR2 1GB 2Rx8 PC2-5300U-555-12-E3   Are these the same? They look like it would plug in. Any help greatly appreciated.
Inspiron 530 RAM compatibility