Comment Re:No (Score 5, Insightful) 671
Once you lose physical control of a machine, you really can't say much about the security of it. You don't know where that laptop has been or who else might have tampered with it while it has been traveling the globe. The best you can really do is the standard antivirus scans. But that doesn't stop a 0-day or a custom written trojan.
You really ought to be treating all portable devices as potentially hostile devices and securing (and monitoring) your networks accordingly.
IMO if the user is competent enough to install Linux or their own custom Windows image on there, I don't think you are any worse off than it was previously. Seeing how out of date some IT departments are with patching and service packs, the machine may end up being more secure.