A new HDD if you want, because given the age that one will be slow even compared to a current laptop HDD.
A used Turion 64 X2 TL-68 for 5$ from ebay, a pair of 2GB DDR2 SO-DIMM sticks to up it to 4GB of RAM, a nice deep cleaning, clean heatsink, clean fan, repaste, clean all the chassis while its apart.
If you want windows, just download it using media creation tool and install it via an USB pen, the laptop should be able to boot from the USB drive, and try it out, everything should work, no need to install drivers from dubious websites, you dont need to BUY windows, just live with the watermark on the bottom right corner.
Or put some ubuntu in it and give it a try as well.