Slice tool not working (Windows)

Started a trial with Photoshop V11 and I'm having troubles with slicing. Firstly the slice tool isn't in my toolbox, and secondly when I press K which I think is the correct shortcut key - my cursor changes to a circle with a line through it (banned).

It is happening on any PSD file that I'm opening.

If I try saving for Web and using the slice tool which is on that toolbar, I can create a box around something but as soon as I finish dragging with the mouse the square disappears. It is as if I really am banned from slicing - and I don't know why.

Check your view settings to actually show the slices. This may simply be turned off (though the slices would still appear in the "Save for Web" dialog). The shortcut is incorrect for CS4. K has been assigned to 3D item transform. Slice is a subset of the crop tool now, so C is the default shortcut. Feel free to change it back or use a different shortcut set...

Mylenium