Older notebooks may have 2.5″ IDE (Parallel ATA) hard drives, they can still be updated but supply of new IDE drives is drying up. Netbooks, Tablets and Ultra portable machines may have mSATA or 1.8″ SATA ZIF or PATA ZIF drives, call a dealer for compatibility information.
I recommend that along with your new hard drive or SSD drive, you purchase a USB – SATA 2.5″ drive enclosure for about $20. This makes transferring your data from the original drive very easy. Before removing the old drive, install the new hard drive into the external case and attach it by USB. Then clone the internal drive to the external, which will copy the operating system, programs, data and everything.
Instructions for cloning the drive https://computer-answers.ca/2012/computer-questions/windows-questions/q-how-do-i-clone-my-windows-7-drive-to-a-new-hard-drive/
Then physically swap the two drives, installing the new drive in the notebook, and putting the old drive into the USB case, for use as a backup or data transport drive.
In most machines, the hard drive is accessible behind a trap door on the bottom of the machine, held in place by one to four small Philips #00 screws. Slim notebooks and aluminum bodied machines may need to be disassembled more thoroughly, please refer to your owner’s manual. If you are not confident, take the machine to a competent tech.
On the original drive you may find that the plug-in pins on the hard drive do not match the standard SATA power and data connectors. If this is the case, more than likely there is a proprietary adapter attached to the SATA connectors to make the drive fit the machine’s data and power sockets. This adapter and any other caddy or mounting hardware that comes out with the old drive, will have to be transferred to the new one. Gently pry the adapter straight back from the hard drive to release it from the SATA connectors.