Wifi & registry errors

iyogi is a "service" that charges you for their "tech support." Given that they said some garbage about "91 registry errors" that's all I need to know to put them in the same harmful category as so-called "Registry Cleaners" (actually registry wreckers). The only way I would consider letting them touch my computer is if they bought it for full price.

You mentioned that you have Norton disabled. If you don't want networking problems uninstall Norton and run Symantec's Norton Removal Tool. If desired you can then reinstall Norton, but keep it enabled and fully paid for.

Any two anti-virus programs will conflict; never have multiple anti-viruses or firewalls running. It's OK to have multiple anti-spyware applications running.

You remove (delete) junk files the same way you remove non-junk files that you no longer want. When you Restart (or shut down and then boot fresh) Windows does some housecleaning, including with the Registry. There is no way to prevent a few errors except by never using the system. Very seldom will you get any troublesome registry error unless you use a Registry "Cleaner" (or, apparently, iyogi). If you get a serious registry problem there will likely be something about it on the internet and/or somebody here will be able to help.

I don't know what "junk" files you are talking about, but you should be running Disk Cleanup periodically.