I have a question regarding a harddrive upgrade in my laptop. The laptop is a HP Pavilion zd7040us bought in Feb. 2004. It came with a Toshiba (mk6021gas) 60GB 4200 ATA-5 harddrive that recently died. I'm looking to upgrade to a Seagate (ST9100824A) 100GB 5400.2 ATA-6 drive. I would assume that an ATA-6 drive is backward compatable with a ATA-5 system, but I'm not that familiar with the ATA-2/3/4/5/6 standards. I emailed HP support asking if the ATA-6 drive is compatable the laptop. Here is their response: "the Mother board of the Notebook is configured in such a way that the maximum speed of Hard Drive that it can support is 4200RPM. However, if you will use the 5400RPM Hard drive, it will run at a maximum speed of 4200RPM only. Since your Notebook goes with the ATA-5 Hard Drive, you cannot use ATA-6 Hard drive with it. Using ATA-6 Hard Drive will cause compatibility issue." This just doesn't sound right to me. Does the motherboard actually have control over the spindle speed in the HDD? Can anybody offer any additional information regarding this issue? Thanks.