Re installing CE 7.1 error message

Hi Experts,

While Re installing CE 7.1 i am getting the error message

An error occurred while processing option SAP NetWeaver CE Developer Edition > Install SAP NetWeaver CE Developer Edition( Last error reported by the step :The system is inconsistent. Registry or SAP_DBTech information is available, but software is not complete.). You can now:

u2022 Choose Retry to repeat the current step.

u2022 Choose View Log to get more information about the error.

u2022 Stop the option and continue with it later.

Log files are written to C:\Program Files/sapinst_instdir/CE71_DEV_ADA/INSTALL.

So can you direct to me how can be solve the same problem

Regards

Ishikesh