[mzltest]

Well, we've only one PC, so next time if there's a thread about mobile, I might be able to give a better reply, but yeah for the time being here's what exists. 

My Main PC (Desktop)

OS: Windows 7 Professional 32-bit.
Antivirus: Ivanti (KaperSky).
Firewall: Windows Defender Firewall (builtin).
Virt: None. It's used for mainly by my Dad for work, and the company has put in enough of their software to prevent messing around with it. 
HIPS: Windows defender built-in rules.
Encryption: WinMagic SecureDoc.

Personally I don't think mobile need to rely on antivirus much as long as you use App Store/Google Play as the only source for app as the antivirus for phone really can't do much due to permissions.

It seems to be an old PC as it still uses Windows 7.Personally I suggest using a user-level account rather than admin account for daily use if your dad don't have the need to install new softwares frequently and the software used for work is also usable in user level.(Of course,if your dad is an experienced user youprobably don't need this)