The basic things you need to do now:
Start into a recovery console from your Windows installation CD (select R for repair after booting it) and type the following two commands:
chkdsk c: /r /p
fixmbr
Then reboot.
The first command checks the filesystem for errors and fixes them for you. The the second command makes sure the part of the HDD that says which partition to boot is set to boot directly into Windows (which it probably is already if Windows can boot and show a blue screen, but just in case we'll run it anyway).
If that doesn't fix your problem, check the time in the BIOS to make sure it's correct. Try booting one more time and then re-install Windows, because if it hasn't worked yet your filesystem is broken beyond repair.
Now if you have a brand-name computer and you don't have a Windows installation CD, we can look up the manufacturer's solution on their website. They should have some way to fix it, and if not, you can always send it in on warranty.