my computer was running slow so i delete the temp files from my computer , i did only three steps: 1- ) delete temp ,%temp% 2 - ) ran del tmp *./s in cmd before that cd.. , cd.. change the directory twice to go to the c : 3 - ) refresh the firefox and reset the chrome 4 - ) restart the computer after that i checked in my thunderbird mail all the folders that i had got deleted ... so please tell me where did i made the mistake due to which i lost my thunderbird folders....