I'm not familiar with your model PC, but any modern HD that is 120G or less should work in your machine. I would stick with a 7400 rpm drive if I could. IF the BIOS supports 48bit LBA addressing, you can break the 137G limitation. Google that or ask HP. Rick Glazier From: <Phillipwlly >I am looking to replace an aging Hard Drive in my Compaq Presario 5425ks > desktop. The HP/Compaq site lists my HD as an 80GB (5400 rpm) Ultra DMA. > Browsing HDs at Newegg and TigerDirect, the term "UltraDMA" isn't used so I'm unsure > of what drives might be compatible. I'm leaning toward either WD or Seagate > 80GB 7200 rpm at an "affordable" price. > Are there other terms or associated numbers I should look for while shopping? The NOSPIN Group has added a new feature on our website, web based bulletinboard for questions and answers: Visit our sister website at http://nospin.com