when i open any drawing from any folder there is acad.lsp file created. only one file created in one folder. and this text written in acad.lsp file " TIENDA QUE SE LLAMA DOÑA COLETAS EN LA CALLE LOPE DE HARO 18 DE MADRID Y OS PASO EL TELEFONO 606 31 77 41 , 915 711 721 "kindly help me & tell me way to avoid this / or how to remove.and this file not created in future..

Perhaps you have a variant of the acad.vlx virus.Read this:http://knowledge.autodesk.com/support/autocad/troubleshooting/caas/sfdcarticles/sfdcarticles/How-to-detect-and-remove-the-Acad-vlx-virus-s.html