setup and deployment

Question

I have created a setup for my project. I include framwork, crystel report and sql express in my setup file.
but when i try to install setup in my fresh computer that dont have sql Server, is showing following error:-

Setup has detected that the publisher of file 'C:\DOCUME~1\DELL\LOCALS~1\Temp\VSD189.tmp\SqlExpress\sqlexpr32.exe' cannot be verified.

I am not getting this error.
Please help me