|"i want install windows 7 but my motherboard not supported!"|
Where did you get that info from?
"how can update my motherboard pc?"
The only way to update a motherboard is to buy a new one. How about posting the make/model of your current board along with the rest of your system specs. If you don't have at least 1GB RAM (2GB or more is recommended), you're wasting your time with Windows 7.