Windows XP SP3
Intel Core 2 Duo E8500
Mobo; GA-X48-DQ6
video; ASUS ENGTX460
Ram; OCZ3G18002G X2
Mobos on-board Realtek HD audio.

Hi guys, Monday evening my computer was working perfectly. I am the only person who uses the computer. I came back a few hours later, and went to close a folder window, It lagged and it took ~3 minutes to close.
-I shut down my computer and went into safe mode. It seemed to boot at normal speed then really slow when Windows started. it took ~10 minutes from 'Welcome' to fully loaded desktop.
Everything is taking a really long time to do.
-I ran Malwarebytes. Clean. (took ~7 hours, normally TAKES ~1 on my system)
-I ran AVG. Clean.
-I attempted to delete some extra folders cluttering my desktop and the computer lagged out and froze. I LEFT it for 40 min an then restarted it.
-I Figured it may be my ram, so I swapped out my current ram for an old pair that I know was functioning when last used.
No changes.
-Swapped ram back.
-I attempted a system restore. It failed. Could not copy files. (Have lots and lots of space)
-I attempted an XP repair install, leaving it to go while I slept. it failed. Worked to 35% then said it couldn't copy files.
-I formated my master drive.
-I attempted an XP re-install. It failed. Worked to 30% then said it couldn't copy files.
-I figured my HD may be messing up, I opened up the case again and saw that the wire for my internal speaker got unplugged. I plugged it back in and booted up to see what it did.
Now I am getting a long beep that just keeps going.
My Manual says that is the code for Gfx card not inserted properly.
I also currently have my main case fan disabled, I'm running a different case fan from an external power supply. Beep could be related to my case fan being broken.
-I reseated my gfx card and still get the beep. However It don't seem to me like a gfx issue. I have had not gfx problems. and while slow to run everything LOOKS just fine. regardless I Reseated it SEVERAL more times, no change.
-Thinking 'maybe the ram' again based on the beep I swapped the ram to other slots. no change.
-Swapped em back, and here I am. Not sure what to do next.

They are all hypothesis; but I'm thinking HD failure or Mobo failure b/c of the beep, Maybe processor?

Can someone please help? Many many advanced thanks. Quote

A: The following Award BIOS beep code descriptions may help you identify possible computer problems. (For reference only.) 1 short: System boots successfully 2 short: CMOS setting error 1 long, 1 short: Memory or motherboard error 1 long, 2 short: Monitor or graphics card error 1 long, 3 short: Keyboard error 1 long, 9 short: BIOS ROM error Continuous long beeps: Graphics card not inserted properly Continuous short beeps: Power error GA-X48-DQ6 Motherboard - 110 -