most probably your Windows OS has gathered several programs which pointlessly load on boot (as most internet computers do)
go to start >> run >> msconfig.exe
that will open up a new window, click on the "Startup" tab and there will be a list of all the non-windows programs which open on startup. Take a good look and disable all the ones you dont need.
restart and computer and it should load much quicker
p.s. if you uncheck anything you do need, no worries simply open up the startup tab again and recheck it.
- your 2ghz computer should be more than enough to boot a clean installation of Windows within 10 - 15 seconds.