Guyz i have downloaded so many isos but none of them are working my computer specs are below plz guide me or point me to the right direction please

Core 2 Duo 2 GHz Installed Memory
3 GB (DDR2 SDRAM) Hard Drive
250 GB Serial ATA, 5400 RPM
Display 16.4 in. XBRITE-ECO
LCD Operating System Microsoft Windows Vista Home Premium Mobile Centrino Mobile Technology Processor
Core 2 Duo Processor Number T5800 Processor Speed 2 GHz
Motherboard Chipset Intel GM45
Express Bus Speed 800 MHz
Memory Installed RAM 3 GB RAM Technology DDR2 SDRAM
Max Supported RAM 8 GB RAM Speed 800 MHz
Installed Cache Memory 2048 KB
Hard Drive Hard Drive Capacity 250 GB Hard Drive Rotation Speed 5,400 RPM
Storage Controller Type Serial ATA
Display Tech XBRITE-ECO LCD Screen Size 16.4 in. Display Max. Resolution 1600 x 900 Video Graphic Processor Intel Graphics Media Accelerator (GMA)
how can i install please direct me