If by droid you mean a phone that's branded "Droid", that is a Verizon brand name, so you should speak to Verizon.
If you just mean "android phone" then I'm afraid we'll need more information - what phone you have, where/when you got it, what network you are trying to use it on, any messages it produces, what you see if you scan for available networks. You can either post again using the same form (because you won't be able to reply to this), providing as much information as you can, or if you prefer you could register with the forum, which would be easier if we need to keep a discussion going to work this out.