|Try Startup in SafeMode.|
Try holding down F8 during bootup, select Safe Mode from the Menu. If it starts in Safemode you may have a Driver Problem.
Look in Device Manager for Yellow "?" or "!". Right click on the Device with Yellow, select Uninstall, then reboot.
To Get to Device Manager, Click Start>right Click My Computer>select Properties, click the Hardware Tab, click on Device Manager tab.
If more than one device is marked, Uninstall 1 at a time. Write down which devices are Marked in Yellow.
The un-installed device will be re detected and installed on boot up. Watch the Ballon Pop-up by the System Tray (Clock) and wait till the process is finished.
Post back here with results.
Write down DETAILS of any Error messages you may see.
There is nothing to learn from someone who already agrees with you.