If it's been installed by a relative it will be a legitimate product, and therefore may well be ignored by security software, but...
Try this:
Firstly, boot your computer to the Safe Mode menu screen. You do this by repeatedly pressing F8 as soon as you boot up. Once there, use the arrow keys to highlight Safe Mode with Networking. Continue to boot from there, by pressing Enter. You will now see some drivers being loaded. There will be a pause at some point. This usually lasts for no more than 30 seconds.
If that’s successful, open your browser, copy and paste this link into the address bar and press Enter. It's a direct download for RKill. Save it to your desktop, then run it. It takes just a minute to run. As it's running, any remaining desktop icons will vanish for a few seconds. When the notepad report is displayed, just close it.
http://download.bleepingcomputer.com/grinler/rkill.exe
RKill SHOULD HAVE STOPPED THE INFECTION(S) FROM RUNNING, BUT IT WON'T HAVE REMOVED IT / THEM.
Now download this package.
When you click on the download button, wait for a few seconds and the download box will appear, without you having to enter your name or email address.
Save it to your desktop, unzip it...click on start.exe...then click on Emergency Kit Scanner. Wait for it to open (this may take a couple of minutes), then get updates and run a Deep Scan (the scan may take some time):
http://www.emsisoft.com/en/software/eek/
You should now delete RKill, as updated versions are often made available.
After this, try rebooting normally.
Hope this helps.