A Problem Inside Of Another Problem...!

Hello all,

I have an older computer, an AMD FX53 processor with 3gb ram, a Geforce 6800 Ultra on an AGP bus, and two 160gb hard drives running Raid 0, using Win XP home (OEM), SP2.

I recently replaced Norton Antivirus 2006 with Norton 360 on this older unit.

The first problem:
My wife ran into an error when booting up. The unit booted up to the screen where I see the Microsoft logo, and the horizontal progress bar...then the screen goes dark for maybe 30 seconds, and a blue screen comes up. The message

Unknown Hard Error
C0000218

flies by, and the unit reboots. Continuously.
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The second problem:
My wife tried to fix it by going into Setup. She said it had been happening once in a while, and she got past the problem by pressing ALT+F8, but it finally would not take that. So she got into Setup, and somehow ended up in the Set Up Password area. She got out of that by setting a password to enter Setup. She did not record the new password correctly.

So, I can't get into Setup to reset the unit to allow me to boot from the CD, so I can try my recovery disk (OEM version of Win XP.)
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I note another thread mentioning a problem like this called "New HD Needed" and a reply mentioning the use of www.ultimatebootcd.com to diagnose the problem.

I am not sure I understand the phrase "burning the iso" but I assume I can go to the site, download a file and burn it to disc? My new unit runs Win Vista HomePremium. I'll try to get that file and get it burned to disc using what comes with Vista.

But, is the Raid 0 arrangement on that old unit going to muck things up? And how do I get past the password protection on Setup to reset to boot from CD first? (Boots straight from hard drive presently.)

Thanks in advance !