Motherboard or Windows?

[Sakumo]

I'd say motherboard, AFAIK windows will not cause POST beeps.

If you have a spare hard drive somewhere you can try to see if it's windows causing the problem by installing an OS on that HDD. But I'd say it's highly unlikely.

PS your sig kinda scares me

[woshiibreak]

I'm sure the beeping is not the POST beep, as Windows wouldn't start at all if it were.

[SnOwBunZz]

http://www.computerhope.com/beep.htm

This should cover the part of 'which beep code means what'.
I can't really find out which code you have exactly in the way you described it.

[Ronin]

Are you sure that the PSU is doing good?
To me your problem sounds like capacitor damage on the first hunch.

However,

Is your setup a custom build, or built on top of a complete system?
Whats your PSU?
Do you have any spares for testing?

@SnOwBunZz:
I have yet in my life to see a BIOS that correctly adheres to POST sound-code "standards".

[SnOwBunZz]

@SnOwBunZz:
I have yet in my life to see a BIOS that correctly adheres to POST sound-code "standards".

It's still a step closer to knowing what the beeps mean. I could search for the exact meaning of the beep as long she would post clearly how it beeps (or meaning me less drunk, since I'm on a Polish b-day party, which you should read as quite a bit of alcohol) and who made the BIOS (ami-bios, phoenix etc).

[woshiibreak]

Yes, it is a custom built. PSU is Corsair 650W. I'll test with a spare and see how it goes.

@snowbunzz
Like I said, I'm pretty sure it's not the POST beep that is the "beeping" that I am referring to that is happening. The beeping happens after the POST, while Windows is loading. The beep is much like the beep that indicates the computer is overheating, but the computer starts fine and runs without any trouble.


Updated original post with more information.

[Ronin]

Well I understand the following:
When you boot a PC, the motherboard does a "power on self-test".
Every signal during that time is a POST notification.

You say that the beep occurs after this test is already finished?

@USB:
I had various issues with USB peripherals connected on boot.

I am not completely clear on what kind of testing you did;
As I read it you did the following two which did not change the problem "significantly":
- Boot minimal config (no mouse, no additional HD, no disk drive, no floppy, one RAM, no case fans, no peripherals, no networking)
- Boot normal config with no USBs at startup (some USB devices are just problematic; That for me includes my ipod btw)

You could to make it definite that it's not a POST, take out one piece of hardware from the minimal config and check if the bootup process works out like before (try booting no RAM, not video card, no monitor, etc.), thought you should be able to see the ram check if you did disable the BIOS logo.

btw, using 2 brands of RAM together is already risky business in the compatibility department.
Did you try shuffling them around, or is there a recommended setup in the documentation?

However, there are steps I would recommend (do any you didn't already do);
Check all connections especially the power lines of the PSU (unplug, plug in again)
Set your fan speeds to continuous in BIOS (and/or load a fail safe mode)
Check that the BIOS battery is not depleted and/or badly connected