Hi there,
I am sorry but your description of the problem doesn't make it easy for us on the forum to help you.
When you say it takes a long time to power on do you mean that it takes a long time to get into Windows or other Operating System?
Or does it take a long time to get through the POST/BOOT Process?
It would help if you could post back with a list of your system parts, Processor, RAM, Harddrive(s), DVD/CD Drive(s), Graphics card, Power Supply and any other hardware you have installed or attached to the PC such as make of Keyboard, Mouse, Monitor and any other USB Devices.
Or, if it would be easier to use your native language you might do better to contact Technical Support via this link:
http://ggts.gigabyte.com/tech.asp?ClassID=2&Country=Malaysia&SourceWeb=B2C