It depends on where you get the receiver.PK6301 said:
If you buy a used but NOT LEASED receiver (not from DirecTV or an online RETAILER) and install it yourself your contract will not be affected. But if you order a receiver from DirecTV, YOUR CONTRACT WILL BE EXTENDED. I believe standard SD receivers do not add a full 2 years to the contract, but don't quote me. It used to be a year.