Serious system crash

My home PC crashed again!

I usually hibernate my system every night when I go to bed so it'll wake up faster the next day. The last reboot I did was after the ZoneAlarm problem.
My Firefox can't connect to internet properly yesterday morning, so I decided to give it a reboot. But it kept coming back to the screen asking me to choose SafeMode or Normal Boot. And the normal boot will stop after the WinXP splash screen came up for a while then a blue screen showed up for half a second and then reboot itself and brought me back to the choosing Safemode/Mornal boot screen.

I managed to take a photo of the blue screen and it has

Technical information:
**STOP: 0x0000007E (0xC00000??,

The "??," are gibberish that I cannot make out, seems like it rebooted before it showed everything.

I could still get into safemode (without Network support) and back up whatever I want to back up. And I thought I'd just reinstall the OS.

But the real scary thing is after I changed the Boot priority to "Boot from CD" and nothing else, and rebooted with my XP CD in the CDROM. It gave me an Error of "System Halted" on a black screen. So I cannot even boot from CD!!!

Seems like this time is a big one! Can anyone shed some light on what may go wrong?
My system is probably 4-5 years old now. Don't just die like that, please!!

I hope it's not Horatio trying to straighten things up and I stuffed it up again...