You have a failure that is specific to the USB system on your computer. The fact that you have not run just one but two different programs and both have come up with nothing suggest that it isn't a virus, combine that with the fact you have an AV program running and that is three different anti virus software programs that have all been defeated by this 'virus'. Unlikely, even the worst of these would at least give some sort of suggestion of a virus or program doing something it shouldn't but all three and nothing... unlikely.
The internet failure, the issues with Mcafee, the overall slowness of the PC can all be linked in one way or another to a corrupt USB driver or worse a failure of the USB hardware itself.
At boot Windows will attempt to intiliase all devices connected to the PC, that includes the USB hubs as well as the devices connected. If their is a corrupt or damaged component to the USB ports then Windows can get stuck in a constant loop looking for a way to initialise the devices.
Mcafee will spaz out because it's on access scan will attempt to scan any device connected to it, if the USB drive is there but not working their is a chance the active scan part of the software is waiting until Windows successfully initialises the device before it loads the active scan software.
Your internet isn't working because it requires your USB ports to be working, if they don't work your internet access point won't work either.
System restore won't work, if by won't work you mean it doesn't resolve the slowness and the issues then that makes sense system restore can't fix a hardware issue, although it could very well resolve a corrupt driver issue.
Finally, and I am sick of saying this.
a). You have a problem but have provided NO information about your system. The Operating system would be a nice start
b). The folk here know nothing about computers, seriously they have all assumed that you have a virus and all reached the conclusion that you should save data and reformat. Even given the basic information needed to reach a preliminary conclusion, if anyone's first answer is backup data and reformat then their advice isn't worth listening too. Anyone that suggests that without any real information, ala this topic so far, then they are an idiot.
If you are someone who has replied and feel that I have some how slighted you by calling you an idiot, then please reread your advice to the OP. If it contains the words' backup' and 'reformat' and doesn't at any point ask the Op for more information about his computer... then yes you're an idiot and I don't really care what you have to say on the fact.
Finally a very quick test for the OP to try.
If it is indeed a USB issue and it is indeed a software issue you can force Windows to reload them by going to device manager finding the entry that refers to 'universal serial bus controllers' and then uninstall these. Shut down and reboot and Windows will reload the USB drivers, it may however ask for the original installation disc to do this.
