log using

hi friends. i am run this code but faced with error.although it is run without error yesterday, i am confused please help me
code:
log using "C:\Users\A1duneh\Desktop\CollateralChannel\ou tput/reg.log",replace
error:
file C:\Users\A1duneh\Desktop\CollateralChannel\output/reg.log cannot be modified or erased; likely cause is read-only directory or file
r(608);