IDE cables were commonly used into the early 2000s which is when SATA started to take over.
512MB is ok for Windows XP but beyond that, it's going to be painfully slow with lots of disk swapping. RAM is pretty cheap these days for older computers. That motherboard can support up to 2 GB which would be better a lot better for Windows 7.
Yes, I have to look for some RAM of this model to expand the memory, but the computer only had one and it's not easy to get here.
And yes, it has 4 slots so if I manage to find 3 of 512 I will manage to expand its memory.