Windows 7: USB ports randomly freeze

USB ports keep freezing –
Mostly my mouse and sometimes my keyboard keep freezing – at least 2 times per hour.
Sometimes the whole system freezes and I need to unplug the power to reboot.
I often hear the bebop sounds of a usb port responding to input/removal of a device
Sometimes when it freezes it recuperates after 1 minute and system gives message in system tray that my usb device has been installed successfully.
Sometimes if I switch the device to a different usb port, it works.
I have tried updateing drivers and windows in general,uninstalling the usb ports, set power mangement to disable turnning off device....
My machine has been stable for about 6 months and this just started happening.
Any ideas?

Scan your system for viruses (Update your scanner first) using your preferred anti-malware software or I suggest getting Malwarebytes' Anti-Malware

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