I was thinking of getting this program (PSP

but I don't really understand GB and MB. I was hoping someone could help.
If my computer is this:
Processor: 1.6 GHz AMD Mobile Sempron 2600+
Memory: 256MB DDR SDRAM, Support DDR 333/ 400 SDRAM, up to 1.0GB total
Hard Drive: 40 GB HDD
Operating System: Windows XP Home Edition with Service Pack 2
Graphics: Internal Ultra256 2D/3D graphics, Built-in High Performance 256-bit 3D Engine
Will PSP 8 fit and work on my system if the statisics above are what I have on my PC? I guess I'm just wondering if a 2GB or 40GB or 80GB makes a difference... Because it says PSP 8 takes 75MB hard rive space....It's all so confusing

.... I would be really pleased if it worked on a 2GB system...I want to get a cheap laptop to put this program on. Would that work?
Please help. Thanks!