If this is a new computer that the "shop" built, then yes, I would take it back and ask them to make things work correctly. It's the least they can do if they built it.
In regards to the hard drive and mouse noise, it sounds like the power supply bus is routing sound back through the sound card . Here's a link with someone else that has the same issue:
Noises from mouse and hard drive from speakers
Hope this helps.
I have built a new PC and when the hard drive is busy you can hear it through the speakers - it sounds like a strong wind!!Also as i move the mouse you can hear noise through the speakers.Any ideas what is causing this noise and can i do anything to stop it?The system is a 2.8 P4 , 512 DDR400 , Eagle case with 500w power supply,Hercules 9800se video card , Abit IS7 Mobo.Also the tv tuner on the video card does not work - all the drivers are installed , the video capture is fine using composite and s-video but the tuner wont work - anyone had problems with this , do i just take it back to the shop?