cmd.exe corrupted
cmd.exe is a command line program for Microsoft Windows systems, similar to Microsoft's DOS operating system. cmd.exe is a 16/32-bit command line program running on Windows NT/2000/XP/2003/Vista/7/8. This is not a purely system program, but if terminated it may cause unknown problems.
Double-click My Computer, right-click the C drive and select Properties, Tools, Errors (Start Checking), check Automatically repair file system errors, and start. It will prompt that it cannot be repaired and ask you if you want to repair it the next time you turn on the computer. If you choose yes, don't do anything on the next restart until the startup is completed.