the repeating sounds may also be due to the slow PC you have, making it lag.
You shouldn't have stealth objects in recyclers, we can try to clean them and see if that solves your problem but if you are sending the PC to the shop then there is no point continuing here. Let me know and I will see what I can do
Or like Dieselman said, you can use Dban and wipe your drive again and see what happens.
Real-time protection: Avira, Comodo Firewall and D+, Malwarebytes Pro
OS: Vista 32-bit