Comment You don't (Score 2) 408
Simple as that, you don't, it's just not possible....
I'd start with Avast, maybe Malwarebytes. Install Chrome, put it on their desktop and change the icon to Internet Explorer. Use SpyBot to blacklist sites. Setup everything to auto-update and auto-scan so they don't have to be bothered with any of it.
Then come back in a month, Secunda PSI and Qualys Browser give you a good way to keep track of what needs to be updated. Update it all. Registry doesn't really need to be cleaned these days, unless it gets really bad, I've found it actually does help performance a bit, CCleaner does a good job of this. Make sure everything is up to date and clean. Now go to the Control Panel, uninstall all the toolbars, uninstall Mcafee, etc.
Repeat this process every month... You can make things better, but you can't secure it.
I'd start with Avast, maybe Malwarebytes. Install Chrome, put it on their desktop and change the icon to Internet Explorer. Use SpyBot to blacklist sites. Setup everything to auto-update and auto-scan so they don't have to be bothered with any of it.
Then come back in a month, Secunda PSI and Qualys Browser give you a good way to keep track of what needs to be updated. Update it all. Registry doesn't really need to be cleaned these days, unless it gets really bad, I've found it actually does help performance a bit, CCleaner does a good job of this. Make sure everything is up to date and clean. Now go to the Control Panel, uninstall all the toolbars, uninstall Mcafee, etc.
Repeat this process every month... You can make things better, but you can't secure it.