Wifi? Internet issues on one computer

Reset your router and modem, then retest. Also uninstall the virus app per the developers instructions, antivirus apps on Macs are 100% unnecessary as there are no viruses in the wild for OS X. There is a small amount of malware out there that is easily avoided by using a little common sense. That being:

• Do not use torrents for downloading anything!
• If you receive any communication from e-mail, a website, or phone call that advises you the computer is infected it's a scam!!!!!!!!!!
• Only download from trusted sites, if you get an unsolicited email or popup to download something simply don't do it, it's a scam!!!!!!!!

Finally, antivirus apps on OS X tend to create more problems than they solve. They do not offer any, repeat ANY value to OS X and should be uninstalled. The same holds true for cleaning and enhancing apps.

Please test after taking each of the following steps that you haven't already tried. Stop when the problem is resolved. Back up all data before making any changes.

Step 1

Take the applicable steps in this support article. The Wireless Diagnostics program generates a large file of information about your system, which would be used by Apple Engineering in case of a support incident. Don't post the contents here.

Be sure to test on more than one Wi-Fi network, if at all possible. A desktop computer can be tested with a mobile hotspot, such as the hotspot created by a cell phone. If the problem only exists on one network, then the access point of that network should be the focus of your attention, not the computer.

Step 2

Disconnect all USB 3 devices. If you don't know which are USB 3, disconnect all USB devices except keyboard and mouse.

Step 3

If you're not using a wireless keyboard or trackpad, disable Bluetooth by selecting Turn Bluetooth Off from the menu with the Bluetooth icon. If you don't have that menu, open the Bluetooth preference pane in System Preferences and check the box marked Show Bluetooth in menu bar. Test. If you find that Wi-Fi works better with Bluetooth disabled, you should use the 5 GHz Wi-Fi band. Your router may not support it; in that case, you need a new router.

Step 4

Open the Energy Saver pane in System Preferences and unlock the settings, if necessary. Select the Power Adapter tab, if there is one. Uncheck the box marked

Wake for Wi-Fi network access

if it's checked.

Step 5

Open the Network pane in System Preferences and make a note of your settings in the Wi-Fi service. It may be helpful to take screenshots of the various tabs in the preference pane. If the preference pane is locked, unlock it by clicking the padlock icon and entering your administrator password. Delete Wi-Fi from the service list on the left by selecting it and clicking the minus-sign button at the bottom. Then recreate the service by clicking the plus-sign button and following the prompts.

Step 6

In the Wi-Fi settings, select

Advanced... ▹ TCP/IP ▹ Configure IPv6: Link-local only

Click OK and then Apply.

Step 7

Reset the System Management Controller.

Step 8

Reset the PRAM.

Step 9

Launch the Keychain Access application. Search for and delete all AirPort network password items that refer to the network. Make a note of the password first. Turn Wi-Fi off and then back on. You'll be prompted for the password when you reconnect. Save it in the keychain.

Step 10

Make a "Genius" appointment at an Apple Store, or go to another authorized service center.

beverly6060 wrote:

I don't see an uninstall for the ClamXav virus application, but it's been on my computer for several years.

You have correctly concluded that ClamXav is not be related to this particular issue, but if you should ever need to uninstall it, the directions are at How do I uninstall ClamXav completely?