Question:
I have an ACER
Aspire 9504EWSMi
Mod DQ70
Ser# LXA640508255133093ED00
Currently my notebook has Toshiba MK8025GAS 80GB HDD
So i had a few question. Are all notebook hard drives physically the same size?
I know it has to be reloaded with an operating system, I have all the restore disks that came with the computer when I bought it so im good there. I just wanted to know if all HDD are 2.5″,and all the same height. the one I have been looking at is 1 Terabyte Storage capacity for 2.5-inch form factor drives. It also says please note that the drive is 12.5 mm high and may NOT be compatible with all notebook systems. Consult system specifications for maximum allowable drive height before attempting to install.
1TB 5400RPM 8MB Cache 12.5mm 2.5″ SATA Notebook Hard Drive w/ 1 year warranty.
Capacity: 1TB (1000GB)
Buffer Size: 8MB Cache
Rotation Speed: 5400RPM
Interface: SATA/300
Form Factor: 2.5″ Notebook Drive
**(12.5mm height) may NOT be compatible with all notebook systems
Answer:
Yes, all notebook hard drives are 2.5 by 12.5 but they can vary based on interface. The hard drive that you have noted is a SATA hard drive. I believe your notebook takes a older type of connection called IDE or ultra ATA. One way to verify this is to take the drive out of the computer and see what type of interface it has. If it has 2 rows of pins then its IDE. If there are no pins then its SATA. Please note that these hard drives cost more because they are older technology 
Hope this help.
