You can help her computer, its not past fixing. you just have to put more effort into it. Like for me, I picked up some malware on my work laptop not too long ago. the problem is that we're not allowed admin rights to them, so I was limited in what I could do.
Most systems have an option to press Fxx (F1-12) or delete key, etc during boot up. This will allow you to do a safe mode boot up, or restore the system (creating a system restore after doing updates on a stable system is good for sanity). Anyway, this is what I did. get a copy of malware bytes or other anti-malware program (research it first, some claim to be, but are nothing more than malware themselves), and get the installation .exe file saved somewhere accessible like the desktop. Then reboot the system into safe mode WITHOUT networking if at all possible. The reason I say that is often times on deleting/uninstalling hunting it down, it triggers a "silent download and install" of the same program into a different directory. Also, it can cause the anti-malware program to not install properly. I had problems with that where if I wasn't in safe mode and install malware bytes, it would give me fatal errors, but installed in safe mode worked fine. Run the program, let it do the most extensive you can, and just let it run. Odds are it'll find a number of things. Delete them, then reboot back into safe mode and run it again, just to be sure you get the same response. Then reboot normally and run it again, to make sure it doesn't auto-install when booting up normally. You should be good at that point.
and that cost me $0, just a couple hrs of effort. Also, if all else fails, put in the Windows/Mac/Linux disk and do a full format/reinstall of the OS. Rarely do they have malware out there well written enough to survive that anymore.
Then do the things that Kev said, with a couple added ideas:
1)Set up system restores. It's basically a snapshot of your system that you can restore back to if something screws up.
2)Backups. Keep anything you hold precious (photos, financial info, legal docs, etc) on an external hard drive that you can readily disconnect. Put copies of what you want backed up on there, then disconnect it. Check it once a month or so to make sure all the files are still intact, replace any copies that have corrupted. Conversely you could burn those files off onto CD/DVD. They have archival quality discs out there now that have higher quality design and are meant to last a lot longer than the discs you get at wallyworld.
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