Some useful windows keyboard shortcuts.

Copy: CTRL+C

Cut: CTRL+X

Delete an item without sending it to the recycle bin: SHIFT+DEL

Paste: CTRL+V

Select all: CTRL+A

Start menu: CTRL+ESC (or the Windows key)

Switch between open programs: ALT+TAB

CTRL+Z (Undo.)

APPLIES TO
Microsoft Windows Millennium Edition
Microsoft Windows 98 Second Edition
Microsoft Windows 98 Standard Edition
Microsoft Windows 95

You can find more here from Micrisoft.

APPLIES TO
Microsoft Windows XP Home Edition
Microsoft Windows XP Professional

You can find more here from Microsoft.