CPU beeps

The two beeps could be indicating a parity error,with the system mmeory.
The problem could be caused by a bad memory module,check the modules in another system to replicate the error,if so then replace the memory modules

Could be you have installed a program which is set to remind you that another hour has passed. You may be able to see if such a program is set if you enter sounds and audio devices from your control panel (provided you are using some sort of microsoft windows) under sounds and program events. As far as I know products like microsoft Plus! may have such features, sometimes this can be turned on as well if you have a PIM running.

Have a look in the event viewer and see what co incides with the beeps