XP Freezes During Boot-up, Won't Go To Windows

I'm running Windows XP on my desktop. Out of nowhere, the computer stopped working properly; it won't proceed past the black (with Windows in colored letters) screen. The blue status/graphics bar wil scroll but then reach an arbitrary point, stop, and the system won't go any further. I can't enter Windows through Safe Mode. In DOS, I ran CHKDSK on the hard drive that has the operating system on it, but it only gets to 36% before that, too, freezes and stops working. Any suggestions or insight would be most appreciated. Thanks so much.

A couple of things come to mind.

Defective RAM can cause weird problems like this. There are two programs that are normally used to test computer memory, Memtest86+ and Microsoft Memory Diagnostic. They are available from the following locations:

Memtest86+
Microsoft Memory Diagnostic

They are bootable CD ISO images. You don't burn the iso file itself to CD., you create a CD from the iso file using your CD burning software. There is a good freeware burner called ImgBurn which will do this easily.

Also, if you have more than one stick of RAM, remove one and see what happens. If it's the same, put it back and remove the other. That's a good way to test for defective RAM.

Hard drive failure. Power off and unplug the power cord, then open the computer case. See what kind of hard drive you have then go to that manufacturer's web site and download their diagnostic utility and run it to see if there are any problems. The utility will also be a .iso file so you can use ImgBurn to create a bootable CD from it as well.