Error tune keeps going off 5-10 minutes D:

[Ronin]

Ok guys, its kinda creepy. But I keep getting the Error sound in the background every 5-10 minutes. Its beginning to freak me out. I cant find what's causing it, and my computer is clean. I just scanned it. .__. I tried restarting my computer but its still there D:

Anyone know what this is?!

Is it coming from the midi speaker?
It's either some maleware, or your HW failing.
It could be almost anything, your PSU failing, your ram failing, your disks failing or any of the cooled components overheating. You will notice that soon though, but you could still check the temps and the S.M.A.R.T. logs and ram failure rates and the voltages.
For software: best failsafe way is to let hijackthis make a log and research any entry until you know exactly what it is.