My Aunt says that there's always a large blue patch on the screen which won't go away and is always on top of other programs. She says that her computer is also going very slow.
I've advised her to reboot, get updates (from windowsupdate.com), download/run anti-virus and check the graphics card. I think its a problem with the graphics card, but not too sure. Does anybody else know what the problem could be?
It has all the indications of a system overload. Most commonly, there will be many application all running in the background, starting automatically at start-up.
If your aunt has limited resources on the machine, it simply overloads those resources. It's like trying to run XP on a machine that's well underpowered. It looks like XP; is it? If so, get her to click Ctrl+Alt+Delete once only. That will bring up Task Manager and check the applications tab. Tell her to let you know what is running.