The problem(s) started after downloading Realtek audio drivers, installing them, and rebooting. When I click on Start, using Classic Shell, and highlight Programs, almost none of my programs appear. I see 15 folders, mainly to installed programs, and the following: Google Earth, Internet Explorer, Network, Search and Shutdown.

I uninstalled Classic Shell and the same problem exists at the Start screen. There are about 17 tiles, some for programs I use, others just W8 "clutter" (like Camera, Music, Video, Maps). Oddly, Excel appears, but its companions Word and Access do not.

If I click on the down-pointing arrow at the left corner, the Apps appear. But the list is far from complete. For example, it doesn't show Mozilla Firefox, Mozilla Thunderbird, MS Word, MS Access. There is no button/tile at the bottom labelled All Apps. There is no Program heading; just Start or Apps.

The Desktop shows shortcuts to my frequently used programs. If I right-click on a program (but not, say, a shortcut to a video) all show the Pin to Taskbar option. Some also show the Pin to Start option, but if I try to do so, I get this error message: No such interface supported.

All the programs are present on my hard drive and work properly. The problem is with the interface.

Thanks for your suggestions.