In order for you to play Plants vs. Zombies GOTY Edition on Windows with minimal graphics settings, your computer must meet the following requirements
OS *:
Windows XP/Vista/7
Processor (CPU):
1.2GHz+ processor
Memory (RAM):
1GB of RAM
Graphics Card:
128MB of video memory, 16-bit or 32-bit color quality
DirectX:
DirectX 8 or later
Hard Drive:
65+MB of free hard drive space
Sound:
DirectX-compatible sound