Windows failed to start?

Okay so i got spyware today on my pc. Then i downloaded a program that found the spyware and said it would erase it. But it said it had to restart the computer to completely remove the spyware. I restarted my computer and its says "windows failed to start. a recent hardware or software change might be the cause." I tried windows memory diagnostic, doesnt work. I tried all the options of starting it, such as safe mode, doesnt work. and i dont have a windows installation disc. I dont know what to do.
this probably isnt gonna help but the file is " CI.dll" and the status is "0xc0000098" and it says windows failed to load because a required file is missing or corrupt.

clean install windows xp?

i bought a xp pro sp3 installation disc but after the installation process i still have my old junk. (i have win xp pro) how can i clean install it???????????!!!

I need a software to repair everything in my windows xp ranging from usb driver to registry. Do you know what the best software for this matter is?
FYI, i lose my xp installation disc and the windows that i want to repair is on my really old laptop which dvd drive is broken.

As far as the driver digital signatures, it crashes right after I see my screensaver and reads me this long error message.

a recent hardware or software change might have installed a file that is signed incorrectly or damaged, or that might be malicious software from an unknown source.
If you have a windows installation disc, insert the disc and restart your computer. Click "repair your computer," and then choose a recovery tool.
Otherwise, to start Windows so you can investigate further, press the ENTER key to display the boot menu, press F8 for Advanced Boot Options, and select Last Known Good. If you understand why the digital signature cannot be verified and want to start Windows without this file, temporarily disable driver signature enforcement.
Status: 0Xc0000428
Info: windows cannot verify the digital signature for this file.

Enter=Continue|Esc=Exit

What I’ve tried so far:
Safe Mode (won’t work)
System Repair (won’t work)
System Check Point (none created)
Okay, it let me in Windows, where do I go from here?

How can I figure out the problem now that I’m actually in Windows now?

I’m paranoid, I feel like any minute it’s about to boot me off and give me that dreaded all blue prompt screen again-lol

Windows failed to start . A recent hardware or software chagne might be the cause. To fix the problem:
1. insert Windows installation disc and restart your computer.
2. Choose you language and click next.
3. Click repair your computer

Other options
Safe mode
safe mode with networking
safe mode with command prompt
Last known good configuration
Start windows normally.

I have done the first option and it just says if the errors were fixed correctly then windows should start normally.
All the other options just load and super fast blue screen flashed and then it reloads everything.
It is a dell inspiron 6400
I am running windows vista home premium 32bit