[vtech]

Not familiar with the specific unit but, I can tell you that just replacing it with a bigger hard drive does NOT automatically give you bigger capacity. The software used to control the drive is the determining factor and must be modified. (if possible)
Several years ago, when I was involved in repairing another brand, the 80GiG hard drive was replaced with a 120~160Gig drive (due to discontinuation) without gaining any additional capacity. At the time, it seemed as it may warrant further investigating but it turned out not to be worth the trouble. To the best of my knowledge, most recorders utilize a Linux operating system which can be modified if you have the tools and know-how.

[alcarr]

I have a DVD player PHILCO HD-DVD-57, it has a 40GB hard disk drive
thus, I am wondering whether I can change a bigger HDD capacity instead
p.e. a 120 GB disk, without causing any malfunction in the system.