My friend gave me a Dell Dimension 2350 running Windows XP. He said "It's got netsky."
I don't know what that is, but I plugged it up and turned it on and after the desktop appeared it made some RANDOM frickin beeping from the motherboard speaker!!! It's soldered on the mobo so I can't unplug it, and it's a file server, already in use, can't turn it off. That beep goes on every morning from 8 to 9 am. It's frickin annoying!!
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Netsky is a virus. Re-install a clean setup of Windows on the system.