Why is my computer freezing up all the time

I am going to havte to copy and paste this here from off a NotePad or else it will

freeze up on me.

I will just tell you things that I noticed when my computer started freezing up on

me:

1. Just a little prior to it, I had removed Nero Essentials from my computer.

Although it is still showing in the Add/Remove panel that it is still there.

2. When my computer started freezing, I noticed my ASUS DVD-RAM Drive

became missing.

3. I had just bought this computer about 4 months ago. I had a HP Pavaillion and

the fan motor started getting really loud, to the point I was ready to just get rid of it.

So I took it to the repair shop and the repair man built me a new computer, which is

now a Packard Bell.

4. I have Windows XP on my computer. And Internet Explorer 8.

5. My computer freezes now when I might be playing a video, the entire screen

freezes up. I have to completely re-start it by pressing the off button, it wont allow

me to do a normal Start/Log off. Then sometimes I just get a black screen on

restart that says Verifying DMI Pool but it doesnt start and I will have to restart it

again, or even wait an hour to restart it.

6. It freezes sometimes when I wake up in the morning. The screen is frozen.

7. It wont allow me to install Java.

8. It freezes sometimes now when I am making a comment on Facebook, or on

You Tube or even here on this forum.