psexec

a) Admin share is enabled: run services.msc and check the 
Service "Server" is enabled
b) Add the key for the share in the registry and restart:
reg add "HKLM\SYSTEM\CurrentControlSet\Services\LanmanServer\Parameters" /v AutoShareServer /t REG_DWORD /d 1

http://stackoverflow.com/questions/15906536/psexec-giving-the-system-cannot-find-the-file-specified

For executable: https://technet.microsoft.com/en-gb/sysinternals/bb897553.aspx

For documentation: http://windowsitpro.com/systems-management/psexec