Windows 7 hangs on boot screen(starting windows)

[sarangbokil.23]

I am using Windows 7 Ultimate edition.It has some problem in loading that it oftenly hangs on boot screen. I wait for 20 minutes but nothing happens. Sometimes when I reset my system it boots up very quickly, but sometimes it doesn't boot for several tries.
There is no problem with installation since I've tried it reinstalling several times. Windows xp runs fine on my pc.
I have following configuration-
Processor-Intel Core2Duo 2.2 GHz
MBoard-Intel D945GCCR
3 GB RAM(2+1)
Graphics-ATI Radeon HD4650 Graphics card of Sapphire
HDD-160 GB seagate hdd (PATA)
Optical Drive-LG DVD RW (SATA)
OS-Windows 7 Ultimate(x86)

Please reply ASAP.
Thanks in advance.

[rkneo11]

try disabling start up programs and try again

[celldweller1591]

Try booting up in safe mode and see where the boot stops at. Write the .dll at which win7 stops booting. We can troubleshoot it afterwards

[sarangbokil.23]

thanks buddy but i've already tried disabling startup programs.Just 4got to mention in post.And it actually happens way before any startup program launching.

---------- Post added at 07:51 PM ---------- Previous post was at 07:51 PM ----------

I'll try this and post about result.Thanks

[celldweller1591]

if you have any PD in any USB port of your system, try booting after removing it. It happened to me that win7 used to freeze at that loading point with my old PD.