Extremely Confusing Hardware problem

[votecaligula]

Hi,
I posted a message on the forum under the Windows category
(http://www.computerhope.com/cgi-bin/yabb/YaBB.cgi?board=1;action=display;num=1132907419)
but now I think it's a hardware problem. I'm getting a post code that I haven't been able to find online. As soon as I turn on the computer I get one long beep it just repeats that beep over and over every couple of seconds and doesn't stop.  The fans are running and the lights are coming on the cd drive, I dunno if that helps explain anything or not.  I only have one RAM stick, and I tried moving it between the two slots, but it does the same thing regardless of which slot its in. Does anyone have an idea on what this code means? I have an HP Pavilion 555e desktop and it has a sticker on the mobo that says "PhoenixBIOS Pentium IV".
Thanks a lot
~Chris

[Frankie]

Long continuous beeps Memory error, but if the beeps are high and low could point to cpu overheating.

[Fed]

Try memtest http://www.memtest.org/