Windows 7 has two virtual keyboards. One of them is called TabTip, the other OSK. TabTip is the default virtual keyboard, and it's ok most of the time. OSK seems to be faster at doing word auto-suggestion. I wish TabTip had the same level of speediness as OSK.
If you are interested in testing OSK you can find it at:
Of course there are other virtual keyboards for Windows 7 which you can find via quick Google search.
You can also modify the side buttons to launch the virtual keyboard with Stephen Perrin's program.
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