I really don't know anything about computers (console player here)
so here it goes:

Windows 7 Home Premium

model: HP G61 Notebook PC
Processor: AMD Athlon II Dual-Core M300 2.00 GHz
Installed memory (RAM): 3.00 GB (2.75 GB usable)
System type: 64-bit Operating System

Display adapters (I'm guessing this is my graphic card)
AMD M880G with ATI Mobility Radeon HD 4200

I hope it well work, but I don't want to give steam $20 until I know it well work.