Disappearing Fonts

I have a client who keeps losing her fonts. She is running Win98SE. If you look in the Fonts Control Panel she only has about 6 fonts installed. When you try to install fonts, at first the fonts cannot be found. When you point the installer at the Windows/Fonts folder it finds the fonts and installs them. But they still do not appear in the folder. If you search for *.ttf the search reveals many fonts in the Windows/Fonts folder. But you cannot see them in
Explorer. You can reinstall the fonts but when you reboot they’re uninstalled again. I also suspect a registry problem. I tried to repair the fonts folder with tweakui but to no avail. Where have all the fonts gone?

Mark