[Peluso]

I want to change my Facebook settings back to my e-mail. A visitor use my computer and now her Facebook page comes up as the primary account and I am unable to change the settings on the Facebook settings tab.

I had contacted a online technical assistance company who wanted to charge me exorbitant fees to correct this problem – I declined; however, the tech did explain that several of my security options under Microsoft have been deactivated by a Trojan Bonjour software?

Do I need to reactivate the Microsoft security softwarein order to reestablish my own e-mail >Removed< and my associated Facebook account as primary on my computer?

[Curlyben]

I want to change my Facebook settings back to my e-mail. A visitor use my computer and now her Facebook page comes up as the primary account and I am unable to change the settings on the Facebook settings tab.

Simply log out and do NOT check the remember me option.
If you have multiple people using this computer then separate COMPUTER accounts might be a good option for security etc.

I had contacted a online technical assistance company who wanted to charge me exorbitant fees to correct this problem – I declined; however, the tech did explain that several of my security options under Microsoft have been deactivated by a Trojan Bonjour software?

Sounds like a reason to justify their fees.
Bonjour is NOT a trojan, but used by Apple systems to communicate and is perfectly fine.

Do I need to reactivate the Microsoft security softwarein order to reestablish my own e-mail >Removed< and my associated Facebook account as primary on my computer?

As long as you have automatic updates activated and an antivirus scanner with malware you'll be fine.
Also surfing with a touch of paranoid mode on helps a great deal, remember the internet is NOT a nice fluffy place, but full of lying scammers that want your cash..