acer aspire no sound disapearing

Sound on my Acer aspire 7520g is disapearing time to time. I've searched web for an answer and everybody writes, that drivers needs to be updated.
That isn't true, drivers are good. Lately I've noticed, that sound comes on, when I pluged a diferrent secondary disk, but only with first boot. Then I expirienced troubles with this disk too. It frozed and after couple chkdsk chekings it crashed down (tried disk on another laptop, but no bios recognition). Then I,ve pluged another disk and voila, sound come on and again only at first boot.
I think it is related to IRQ assigment to devices, but ussualy computer alerts IRQ conflits. But in this case there is no one. When I try to find IRQ assigments to sound card ( when is not working) i cant find any. Only shows couple of " motherboard resources" and that is it.
Is it possible, that computer try to give same IRQ to onboard sata and sound card and that gets it to one who come up first, without IRQ conflict.
I will try with another disk change, so Im asking you, what can I do, if I get a sound next time and get the numers of IRQ assigment for sound card. Is there some reserved IRQ in case of debugging
Thanks

 

Lets begin from Start:
sound desapeared on Windows XP 32bit
No yellow points in device manager
Removed sound drivers and tried with various driver updates from acer and realtek sites(4 of them) no efect
Removed codecs; no efect
Removed Bluetooth Audio driver; no efect
Booted with Linux Ubuntu Live Cd; no sound
Dismentaled notebook for finding loosen connectors
Fresh formated and instaled WIN7 64bit on system disk; No sound
Instaled ceartin drivers ( I think TV card); AFTER REBOOTING SOUND CAME
Checked in device manager and drivers for Realtek HD audio are present
Yellow marking for Coprocesor in Device manager
Instaling Chipset drivers and rebooting: NO SOUND
Tooked secondary disk from computer for Backup on desktop: SOUND CAME
Another rebooting: SOUND GONE
Reinstaling disk drive: No sound, computer requires CHKDSK on disk 2
CHKDSK done before windows started: No sound
Expiriencing troubles with copiying files from Disk 2 to disk 1, Run full diagnostics with DISK DOCTOR on disk 2. Program couldn't finish disk checking, computer frozes.
Hard rebooting with External drive pluged(found new device): SOUND CAME!!!
Copying files from disk2 to external, again dificulties and froze!
Another reboot: no sound, no hard disk2.
Checked in bios; No disk 2
Bought another disk and instaled it, booting (found new device disk) SOUND CAME!!!
Quick formated new disk, copiying files from Disk 1 to disk 2, difficulties!!
Full formating disk2 with no sucsses; computer frozed
Rebooted with WD Lifeguard Live CD and found 180 bad sectors. Returned disk for RMA to local reseler.

Current status:
Acer aspire with no sound and no disk2, with no yellow points in Device mannager

Do you see a patern. Every time there is a new device pluged in, sound comes. This didn't happened only with first restart at WIN7 (why, don't know) and with Linux live CD ( probably there was no sound drivers for this mobo).
Well, I,ve run out of disks. I have USB flash storage for next test but I'm waiting for any confirmation for my suspitions about wrong dedicated IRQs to sound card.

WHAT CAN I DO, IF I get sound at next rebooting?
I will write down IRQ assigments for Realtek audio device, but what's next.
Can I write different IRQ for Audio device in REGEDIT? Is there reserved amount of IRQ adresses for similar problems (when two devices are at conflict, trying to have same IRQ adresses)?

 

In BIOS there is no option for disabling the audio controler.
About BIOS version, I don't realy know. Probably it is not latest.
Thanks for MSINFO32 advice. I will look in it. write ya tommorow.