There are several issues that you need to know about. For the long, sad story concerning indoor antennas, see the lengthy file that I've attached below for you. It explains a lot as to why indoor antennas are, at best, a compromise for the real thing.
In your case, here's some info that may help. The transmitter for channel 2 is located at Colgrave, NY. The transmitter for channel 4 is at Gear Gulf, NY. I have no idea where those are in relation to you, but it may help you in orienting your antenna. See the first link below (scroll down to line 54 and click Buffalo, NY).
Next, you haven't identified your antenna, but as the file below suggests, most indoor antennas are junk. You'll definitely solve your problem with a decent outdoor antenna above the roof or in the attic. If you can't do that because you're in a rental or something, the antenna suggested in the last link would be your best option. If you can't get a channel with that one, it can't be done with an indoor antenna.
Detailed file follows.
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The subject of antennas for digital television (DTV) is incredibly complex, and there are many ways to go astray. Regrettably, indoor antennas are high on that list.
The large quantity of indoor antennas for sale at all kinds of stores may lead you to believe they actually work well. They really don't unless you are quite close to the TV transmitting towers. It's very rare for any viewer to get all desired channels with an indoor antenna of any type. It's almost as rare for anyone to get more than a very few channels with regularity. 60 years ago good TV reception was achieved with an outside antenna mounted as high as possible, and nothing really has changed as far as good antenna design goes.
A huge confusion factor in all this is the fact that most TV stations no longer transmit on their familiar channel numbers, nor in the same TV band (VHF or UHF). Most of them are actually transmitting on UHF; even those with VHF channel numbers like 2 - 13. That makes a big difference in your antenna--VHF antennas suddenly don't work well on channels with VHF channel numbers. It's downright maddening to the uninformed viewer.
The telescoping rods in your indoor antenna are for actual VHF signals, and there are some in almost every metropolitan area. If an indoor antenna is going to work at all for you, you want those rods extended nearly horizontal and broadside to the direction of the TV transmitter. Inside a building, you may find that optimum reception comes by orienting the antenna in what seems to be a wrong direction, but you simply have to use trial and error to find the best position.
With stations transmitting on UHF (the majority), your indoor antenna needs to have some type of UHF element, such as a round loop or small horizontal bars, like a tiny TV antenna. Again, orient the antenna with the bars broadside to the expected direction.
Some indoor antennas have only the 2 rods; no UHF element at all. If that's your antenna, you're pretty much dead on UHF reception.
One thing that may help you is getting the best indoor antenna available, and the experts generally agree that the one in the last link below tops the list. If I was in the market for an indoor antenna, I wouldn't consider anything else. Good luck.
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Followup per some other answers: (1) "The only useful antenna is an outdoor with an amplifier." Nonsense! If you get the right antenna for your location, an amplifier is usually unnecessary and in some cases can make your reception worse. And a lot of people do okay with an indoor antenna if they're lucky enough to be in the the right location with the right antenna.
(2) "Antenna don't work anymore." That person needs to be answering questions on another forum.