In the absence of any more data, our standard checklist and troubleshooting thread:http://www.tomshardware.com/forum/261145-31-read-posting-boot-problems
No beeping? Do you have a system speaker installed (yes, I know Moto asked, but it is important).
Are you reusing your hard drive? If so, you will need to reinstall Windows. Chipset drivers will be incompatible.