A brief description of the error message: http://aumha.org/a/stop.php#0x21a
In short, Windows' security has been compromised - so it won't work until you fix the security issue.
The "0xc0000005" part means that the error occurred in your memory. Most likely this was either caused by the power outage or malware. If the power outage caused it, there may be other damage that isn't obvious at this point.
Since you can't boot into Windows, your choices are a bit limited.
First, I'd suggest that you run this free, bootable memory diagnostic: http://www.memtest86.com/
As a "just to be sure" measure, I'd also run a free, bootable hard drive diagnostic (available at the support website for the manufacturer of your hard drive).
If you pass those 2 tests, then I'd suggest a repair installation of Windows XP. If you have Internet Explorer 7 installed, read this first: http://support.microsoft.com/?kbid=917964
. Then the instructions for the repair install are located here: http://www.michaelstevenstech.com/XPrepairinstall.htm
FWIW - older HP/Compaq's had a System Recovery function that would do a Non-Destructive recovery. This is equivalent to the repair install mentioned above.
My browser caused a flood of traffic, sio my IP address was banned. Hope to fix it soon. Will get back to posting as soon as Im able. - John
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