error report

im getting error reports about C:\WINDOWS\system32\drivers\etc\host and im not sure how to fix this my avg is picking this up and well im hoping it wont cost $$$$$$ can some one help me how to fix this problem also my control panel in add remove programs well its not recognizing the programs i have on my pc and the ones that are there well it cant remove cuz the button is not there??? why is this happening and can i fix this big problem with my windows cd??? and how??