Thomas's mom has an old PC that runs XP and he's trying to convince her to upgrade. Leo says it's a tall order to get people to change as there's over 30% of computers still running XP! Leo says that starting April 8th, Windows XP will no longer be supported by Microsoft, and as such, there may be a 66% greater risk of the computer getting infected online. So it's even more important to get that computer off the Internet after April 8. Even better, get her to upgrade her computer and run Windows 8.1.
Another thing is that if the PC is running so slow, formatting the hard drive (or replacing it altogether) and then reinstalling Windows will speed it up. If she isn't going to upgrade her computer to Windows 8, then maybe putting Windows 7 on it would be a good idea. It may be that all she really needs is an iPad or a Chromebook to do everything she needs to do.
She should also have the latest Windows service packs. She should also be running as a limited user, not an administrator. That's key to avoiding the installation of programs she doesn't want. She should also uninstall Java, and use Google Chrome as her browser. She also may want to look into Trend Micro, which has a special program for XP users.