The old drive is probably IDE (PATA) but it might be SATA. Your netbook is probably SATA so you'd have to determine that first. IDE has two rows of very small pins where the interface attaches. The SATA has two plastic connector tabs, one narrow, one wide. If they're compatible you could use the old one. However back up your data on a flash drive and make sure you have a way to install Windows 7 on the old drive. Make sure you have your windows key written down somewhere, too. It's probably on the back of the netbook.