Dear XXXXX -
Wisconsin is agressive in mailing "estimated" assessments. The purpose of the assessment is to get the taxpayer to file. In almost all cases, the estimated liability is far in excess of the actual tax. Once the return is filed, penalties and interest will based on the actual tax (if any). There will probably be late filing penalties and interest, even if there is no tax, but it will be much less than the assessment. You can expect assessments for 2008 & 2009 if those have not been filed.
You may want to contact a professional to assist you if you find the forms confusing.
what happens if there is no sales for this year and loss for the other years