Any unlocked phone will work on the major network providers (Rogers, Bell, Telus, etc). But for the unlocked phone to work on the other new entrants to the Canadian market (such as Wind and Mobilicity) it has to support AWS. I'm not 100% sure, but I don't think that the HTC Explorer supports this frequency.
If the phone is not unlocked, however, it will not work on any network other than the one it is locked to.
I hope this helps.