Can you look at these build errors please

I get the following build errors:

C:\StockSystemNet\StockSystemNet\PickList.vb Unable to open module file 'C:\StockSystemNet\StockSystemNet\PickList.vb': The system cannot find the file specified.
The custom tool 'CrystalDecisions.VSShell.CodeGen.ReportCodeGenerator' failed while processing the file 'PickList.rpt'.

PickList.vb is not in my directory, nor do i need it.

Whats happening???

In Solution Explorer, expand the References node (by default it is collapsed) - I bet there is a reference to some DLL that isn't there. Should be really obvious which one if this is the case, there will be a red X through the icon on the right of the name of a missing/broken DLL.