It matters as some install XP and bump into that 127GB number. Others know better about that but for most, you can go to newegg.
I have a HP Pavilion tx2500z and I recently found out I had a hard drive by running the built in hard drive test in the BIOS. What I am trying to figure out is if I have to buy the replacement hard drive from HP or can I just go on newegg and buy one with similar specs?
Here are the specs for my laptop, http://www.notebookreview.com/assets/34180.pdf