A
Please uninstall the McAfee product by following these instructions.
Note that if you have already tried to uninstall the software, you may have to reinstall it in order to finish the job. If you have a different version of the product, the procedure may be different.
Back up all data before making any changes. Never install any "anti-virus" or "anti-malware" product again.
B
"TeamViewer" is not working and must either be removed, reinstalled, or updated.
Any third-party software that doesn't install from the App Store or by drag-and-drop into the Applications folder, and uninstall by drag-and-drop to the Trash, is a system modification.
Whenever you remove system modifications, they must be removed completely, and the only way to do that is to use the uninstallation tool, if any, provided by the developers, or to follow their instructions. If the software has been incompletely removed, you may have to re-download or even reinstall it in order to finish the job.
I never install system modifications myself, and except as stated in this comment, I don't know how to uninstall them. You'll have to do your own research to find that information.
Here are some general guidelines to get you started. Suppose you want to remove something called “BrickMyMac” (a hypothetical example.) First, consult the product's Help menu, if there is one, for instructions. Finding none there, look on the developer's website, say www.brickmymac.com. (That may not be the actual name of the site; if necessary, search the Web for the product name.) If you don’t find anything on the website or in your search, contact the developer. While you're waiting for a response, download BrickMyMac.dmg and open it. There may be an application in there such as “Uninstall BrickMyMac.” If not, open “BrickMyMac.pkg” and look for an Uninstall button. The uninstaller might also be accessed by clicking the Customize button, if there is one.
Back up all data before making any changes.
You will generally have to restart the computer in order to complete an uninstallation. Until you do that, there may be no effect, or unpredictable effects.
If you can’t remove software in any other way, you’ll have to erase and install OS X. Never install any third-party software unless you're sure you know how to uninstall it; otherwise you may create problems that are very hard to solve.
Trying to remove complex system modifications by hunting for files by name often will not work and may make the problem worse. The same goes for "utilities" such as "AppCleaner" and the like that purport to remove software.
C
If you still have performance problems after making the above changes, you're probably dealing with a failing startup drive or some other internal hardware fault.
Make a "Genius" appointment at an Apple Store, or go to another authorized service provider. You may have to leave the machine there for several days.
Back up all data on the internal drive(s) before you hand over your computer to anyone. There are ways to back up a computer that isn't fully functional—ask if you need guidance.
If privacy is a concern, erase the data partition(s) with the option to write zeros* (do this only if you have at least two complete, independent backups, and you know how to restore to an empty drive from any of them.) Don’t erase the recovery partition, if present.
Keep your confidential data secure during hardware repair.
Apple recommends that you deauthorize a device in the iTunes Store before having it serviced.
*An SSD doesn't need to be zeroed.