Winchat.exe is a Windows file created by Microsoft Corporation. The file is usually found in C:\Windows\system32 folder. If you find it anywhere else, Please note that winchat.exe could be a virus, trojan, worm, or spyware. Scan your computer with an antivirus software to make sure it is not infected.
Install "Unlocker" and right-click on the desired file and chose to Delete, Rename, Move, Etc. and you are free of that file.
Should the winchat.exe (that you have) actually be a virus, Use your updated Virus scanner to check your system; use utilities such as Malwarebytes or Spybot S & D to scan your system to clean out these types of issues.