@nyev May I recommend any of the harmonic AC conditioners / resonators from Coherence Systems. Their brand is ADD Powr. They work quite well especially for systems with bad power. The Sorcer Apprentice will revive the life in your system. It is a good value of price vs. performance.
Also, for usb ethernet, hdmi digital signal boost the Symphony I/O is a no brainer. It restores the harmonic integrity to your system. They give you 30 days to try anything so you have nothin to lose.