Do you ave windows firewall running on the laptop, If yes do you have file and print sharing allowed. Also worth checking port exceptions if you have customised the communication port within ePo. Winows firewall has caused many similar problems for me in the past?
In addition to Stephen answer please also check that you have Admin$ share available on the epo server of the client on which your pushing the agent, and you are using Domain Admin account while pushing the agent.
Share you can check by: