Now does it just sit there or does it actually freeze.
Try turning of your PC. then turn it back on but this time keep pressing on and off the F8 key. Should get a Advanced Boot Menu. Select Safe mode (Just safe mode) see if it starts up. If it does just try restarting. sometimes that helps. If it doesn't start up into safe mode there could be a couple of things going on. Corruption in Windows, Bad hard drive, ect.