Complaints have been filed by the Department of Consumer Protection against two home improvement companies for not disclosing prior court judgments against them when applying for a state contractor registration or renewal. Hearings are set for September 20 for Angeli Siding & Windows of Wallingford and Kronberg Construction of North Haven, which also allegedly advertised a false registration number on its Web site. The DCP alleges deceptive business practices and conduct likely to mislead or defraud the department.