Many computers take a lot of time to boot (or start ).This is due to many reasons.
Some slight changes can do wonders for your system:
1.Press start->run then type msconfig and press enter.
Go to the startup tab. Here you will see a list of startup items. These are all the programs that automatically start when you boot your PC. It is these that slow down the boot up process.
So uncheck all the unwanted items like ms-office, messengers other utilities that u may not need at startup). Don't uncheck your antivirus software.
Restart your Pc to and see for yourself, your pc will now boot faster....