Hi , i downloaded a few days ago autocad 2013 student version , autodesk gave me a serial number and an activation key for that program. Today i had to work with it , first time i opened it, and it doesn't ask me for any activation/serial number key. I can open the program , but an error appears saying " the drawing file being opened was not created by a product from an autodesk education suite" I have checked that the antivirus gives free permissions to all autodesk products , i am administrator ... also i erased the file "adskflex_00691b00_tsf.data_backup" , as i saw an admin here telling another guy to do that to force the program to run the activation wizard , but it was for activation revit not autocad , and i dont have any folder called "FLEXnet" ---- C:\ProgramData\FLEXnet\adskflex_00691b00_tsf.data C:\ProgramData\FLEXnet\adskflex_00691b00_tsf.data.?backup ---- these are the programs wich was telling him to erase. i just found "adskflex_00691b00_tsf.data_backup" just writting him on the search box , but still any activation wizard. Please help me i should have been working with it long time ago. i am x64 just in case.