Well for one, the BIOS date is wrong.
The first thing I would do would be to install Avast! anti-virus and do a full scan of your computer to determine if it is a virus or malicious program causing this issue. If there is nothing, it most likely has something to do with the hardware side of things.
Be sure to post back here if there was any results!Try opening up the computer's BIOS settings so that way you are not in any operating system environment, so that way there should be no sound coming through the attached speakers. Leave the computer in this state for a while to make sure that no beeps can be heard. If you hear beeps while the computer is idling at this BIOS page, it is most likely something hardware related. If you don't then it probably something to do with your Windows Installation.
Hope everything works out!
Anthony
P.S. This is off topic but that computer seems to be getting a little dated. If your partner is using this for their main driver, I would be looking to upgrade if you had the capacity to! Would make a great gift!