Follow the below steps.
C:\>takeown /r /d y /f cygwin
cygwin is the folder name where is located ours files
C:\>icacls cygwin /t /grant Everyone:F
C:\cygwin\bin>.\cygrunsrv.exe -E sshd
C:\cygwin\bin>.\cygrunsrv.exe -R sshd
Then delete the folder
c:\cygwin and all its sub-folders. This approach worked for me.
Be aware that windows commands like takeown are depending on the locale, i.e. option
/d yworks only in english systems. In german system one needs to use
/d j to work (without hint in the english help, *facepalm microsoft)*