Resetting CEL Light

Just wondering if there is a way of resetting the CEL Light without using VAGCOM. The CEL light came on yesterday after a lead became disconnected, this has been reconnected but the CEL light has stayed on. I tried using vagcom to reset the light but for somereason it will not talk to my car (says canbus not ready on self test).

I would like to be able to reset the light so I know if anything else occurs and requires attention. I shall be contacting supplier about vagcom tomorrow (hope its not something gone wrong on the car).