I remember reading that for Windows 3.1, something like 85% of users never opened more than one window. The taskbar was added to Windows 95 mainly for this reason, but I doubt that the number has changed all that much. People find multi-window interfaces confusing. And the ones that do cotton to them often work exclusively with the mouse.
Following are some very handy shortcuts for Windows 95 use. Unless specified, they work in almost every program in almost every state, i.e. you don't have to see the Edit menu to be able to copy and paste.
Key commands
Shift + arrow keys - select text
Ctrl + Shift + Arrow keys - select text word by word (not letter by letter)
Ctrl + Home - go to top of document
Ctrl + Shift + Home - select text to top of document
Ctrl + End - go to end of documnt
Ctrl + Shift + End - select text to end of document
Ctrl + A - select everythingCtrl + C - copy selected text
Ctrl + X - cut selected text
Ctrl + V - paste selected textAlt + tab - switch between open programs
Browser key commands
Everything above, plus
Alt + left arrow = back
Alt + right arrow = forward
Ctrl + R = reloadAlt + F = File menu
Alt + F, then right arrow = reveal next menu