Computer Freezes at Black Screen

Help me please!

Well, I push the power button on the modem and it's fine... right after the screen does the Windows XP with the loading bar at the bottom screen it turns black and I even left it on for like 10 minutes and it still wont work. I also tried to start windows in SAFE MODE and LAST GOOD CONFIGURATION plus many others, but it wont work. I still have valuable information in the computer so, I want to try to keep "reboot" out of the answers...

Please help me!

 

Have you recently downloaded the "Service Pack 3" from Microsoft?

It would have showed-up as a little reminder in your task bar stating that "updates are ready to be installed" every time you turn your machine on.

 

I seriously don't know what the Sevice Pack 3 is, but I did have those reminders of updates. Are those updates kind of like those when you shut down your computer and they have this icon with the shut down option. If your talking about those, I already updated them all.