No right click on cells in Excel.

[jasonb]

This can happen when certain macro code is executed which disables the right click functionality. To re-enable it, edit the registry as follows:

From this key:

Excel 97:
HKey_CURRENT_USER\Software\Microsoft\Office\8.0\Excel\Microsoft Excel

Excel 2000:
HKey_CURRENT_USER\Software\Microsoft\Office\9.0\Excel\Options

Delete the following entry:

MsoTbCust